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北大慕课（郭炜）：程序设计与算法（一）编程题答案（全）

课程链接：https://www.icourse163.org/course/PKU-1001553023?tid=1464892457
OpenJudge链接：http://cxsjsxmooc.openjudge.cn/2021t1springall/
题目比较多，建议先收藏。
一共有63道题，按OJ上的顺序排列，没有使用超前的知识，跟着课程进度做的，全部在OJ上测试通过。水平有限，欢迎在评论区中讨论。
001:输出第二个整数

# include<iostream>
using namespace std;
int main()
{
	int a, b, c;
	scanf("%d %d %d", &a, &b, &c);
	printf("%d", b);
}

002:字符菱形

# include<iostream>
using namespace std;
int main()
{
	char a;
	scanf("%c", &a);
	printf("  %c  \n", a);
	printf(" %c%c%c \n", a,a,a);
	printf("%c%c%c%c%c\n", a,a,a,a,a);
	printf(" %c%c%c \n", a,a,a);
	printf("  %c  \n", a);
}

003:打印ASCII码

# include<iostream>
using namespace std;
int main()
{
	char a;
	scanf("%c", &a);
	printf("%d", a);
}

004:打印字符

# include<iostream>
using namespace std;
int main()
{
	int a;
	scanf("%d", &a);
	printf("%c", a);
}

005:整型数据类型存储空间大小

# include<iostream>
using namespace std;
int main()
{
	int a;
	short b;
	printf("%d %d", sizeof(a), sizeof(b));
}

006:浮点型数据类型存储空间大小

# include<iostream>
using namespace std;
int main()
{
	float a;
	double b;
	printf("%d %d", sizeof(a), sizeof(b));
}

007:对齐输出

# include<iostream>
using namespace std;
int main()
{
	int a, b, c;
	scanf("%d %d %d", &a, &b, &c);
	printf("%8d %8d %8d", a, b, c);
}

008:输出保留12位小数的浮点数

# include<iostream>
using namespace std;
int main()
{
	double a;
	scanf("%lf", &a);
	printf("%.12f", a);

}

009:空格分隔输出

# include<iostream>
using namespace std;
int main()
{
	char a;
	int b;
	float c;
	double d;
	scanf("%c", &a);
	scanf("%d", &b);
	scanf("%f", &c);
	scanf("%lf", &d);
	printf("%c %d %f %lf", a, b, c, d);
}

010:计算球的体积

# include<iostream>
using namespace std;
int main()
{
	double r;
	double V;
	scanf("%lf", &r);
	V = 4 * 3.14 * r * r * r / 3;
	printf("%.2lf", V);
}

011:大象喝水

# include<iostream>
using namespace std;
int main()
{
	int r;
	int h;
	double V;
	scanf("%d %d", &h, &r);
	V = 3.14 * r * r *h;
	int geshu;
	geshu = int(20000/V)  + 1;
	printf("%d", geshu);
}

012:奇偶数判断

# include<iostream>
using namespace std;
int main()
{
	int n;
	cin >> n;
	if (n % 2 == 1) cout << "odd";
	else cout << "even";
}

013:求一元二次方程的根

#include <iostream> 
#include <cstdio>
#include<cmath>
using namespace std;
double eps = 1e-10;
int main()
{
	double a, b, c, delta,rel,img;
	cin >> a >> b >> c;
	delta = b * b - 4 * a * c;
	if (delta < eps && -delta < eps) 
		printf("x1=x2=%.5f",-b / (2 * a));
	else if (delta < 0) {
		rel = -b / (2 * a);
		img = sqrt(-delta) / (2 * a);
		if (rel < eps && -rel < eps)
			rel = 0;
		printf("x1=%.5f+%.5fi;x2=%.5f-%.5fi", rel, img, rel, img);
	}
	else {
		printf("x1=%.5f;x2=%.5f", (-b + sqrt(delta)) / (2 * a), (-b - sqrt(delta)) / (2 * a));
	}
	return 0;

}

014:点和正方形的关系

# include<iostream>
using namespace std;
int main()
{
	int x, y;
	cin >> x >> y;
	if (x >= -1 && x <= 1) {
		if (y >= -1 && y <= 1) cout << "yes";
		else cout << "no";
	}
	else cout << "no";
	return 0;
}

015:苹果和虫子2

# include<iostream>
using namespace std;
int main()
{
	int n, x, y, geshu;
	cin >> n >> x >> y;
	if (y % x == 0) geshu = n - y / x;
	else geshu = n - y / x - 1;
	if (geshu >= 0) cout << geshu;
	else cout << 0;
	return 0;
}

016:简单计算器

# include<iostream>
using namespace std;
int main()
{
	int x, y;
	char c;
	cin >> x >> y >> c;
	switch (c) {
	case '+':
		cout << x + y;
		break;
	case '-':
		cout << x - y;
		break;
	case '*':
		cout << x * y;
		break;
	case '/':
		if (y == 0) cout << "Divided by zero!";
		else cout << x / y;
		break;
	default:
		cout << "Invalid operator!";
		break;
	}
	return 0;

	
}

017:求整数的和与均值

#include <iostream> 
#include <cstdio>
using namespace std;
int main()
{
	int n,sum=0,a;
	double average;
	cin >> n;
	for (int i = 0;i < n;i++) {
		cin >> a;
		sum += a;
	}
	printf("%d %.5f", sum, double(sum) / n);
}

018:整数序列的元素最大跨度值

# include<iostream>
using namespace std;
int main()
{
	int n, min = 1001, max = -1, num;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> num;
		if (num < min) min = num;
		if (num > max) max = num;
	}
	cout << max - min;
	return 0;
}

019:奥运奖牌计数

# include<iostream>
using namespace std;
int main()
{
	int n, jing, ying, tong;
	int j=0, y=0, t=0;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> jing >> ying >> tong;
		j += jing;
		y += ying;
		t += tong;
	}
	cout << j << " " << y << " " << t << " " << j + y + t;
	return 0;
}

020:乘方计算

# include<iostream>
using namespace std;
int main()
{
	int a, n, out;
	cin >> a >> n;
	out = 1;
	for (int i = 0; i < n; i++) {
		out *= a;
	}
	cout << out;

	return 0;
}

021:鸡尾酒疗法

# include<iostream>
using namespace std;
int main()
{
	int n;
	cin >> n;
	int ji_z, ji_y;
	cin >> ji_z >> ji_y;
	float ji_l = (float)ji_y / ji_z;
	int qi_z, qi_y;
	float qi_l;
	for (int i = 0; i < n - 1; i++) {
		cin >> qi_z >> qi_y;
		qi_l = float(qi_y) / qi_z;
		if ((qi_l - ji_l) < 0.05 && (qi_l - ji_l) > -0.05) cout << "same" << endl;
		if ((qi_l - ji_l) > 0.05) cout << "better" << endl;
		if ((ji_l - qi_l) > 0.05) cout << "worse" << endl;
	}
	return 0;
}

022:角谷猜想

# include<iostream>
using namespace std;
int main()
{
	long long n;
	cin >> n;
	while (n != 1) {
		if (n % 2 == 1) {
			printf("%lld*3+1=%lld\n", n, n * 3 + 1);
			n = n * 3 + 1;
		}
		else {
			printf("%lld/2=%lld\n", n, n / 2);
			n = n / 2;
		}
	}
	cout << "End\n";
	return 0;
}

023:正常血压

# include<iostream>
using namespace std;
int main()
{
	int n,shou,shu,lianxu=0,max_lianxu=0;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> shou >> shu;
		if (shou>=90&&shou<=140) {
			if (shu >= 60 && shu <= 90) {
				lianxu += 1;
				max_lianxu = max(lianxu, max_lianxu);
			}
			else {
				max_lianxu = max(lianxu, max_lianxu);
				lianxu = 0;
			}
		}
		else {
			max_lianxu = max(lianxu, max_lianxu);
			lianxu = 0;
		}
	}
	cout << max_lianxu;
	return 0;
}

024:数字反转

# include<iostream>
using namespace std;
int main()
{
    long long n;
    int diyiwei = 0;
    cin >> n;
    if (n < 0) {
        cout << "-";
        n = -n;
    }
    while (n>0) {
        int yushu = n % 10;
        n = n / 10;
        if (yushu!=0) diyiwei = 1;
        if(yushu!=0||diyiwei==1)
            cout << yushu;
        }
    return 0;
}

025:求特殊自然数

# include<iostream>
using namespace std;
//这个数一定在81-342范围里
int main()
{
    for (int i = 81; i < 343; i++) {
        //转为7进制
        int j = i;
        int yushu11 = j % 7;
        j = j / 7;
        int yushu12 = j % 7;
        j = j / 7;
        int yushu13 = j % 7;
        j = j / 7;
        //转为9进制
        j = i;
        int yushu21 = j % 9;
        j = j / 9;
        int yushu22 = j % 9;
        j = j / 9;
        int yushu23 = j % 9;
        j = j / 9;
        //看是不是相反的关系
        if (yushu11 == yushu23 && yushu12 == yushu22 && yushu13 == yushu21) {
            cout << i<<endl;
            cout << yushu13 << yushu12 << yushu11<<endl;
            cout << yushu23 << yushu22 << yushu21<<endl;
        }
        //是就输出，再找找后面的
    }
    return 0;
}

026:雇佣兵

# include<iostream>
using namespace std;
int main()
{
    int M, N, X, m, n;
    cin >> M >> N >> X;
    //n是当前战斗力，m是当前体力
    n = N;
    m = 0;
    while (n <= M && X > 0) {
        //用能量棒恢复能量
        if (M % n == 0) {
        // 刚好可以用M/n个能量棒回满能量、
            if (X >= M / n) {
                X = X - M / n;
                m = M;
            }
            else {
                /*m = X * n;
                X = 0;*/
                break;
            }
        }
        else {
        //得多用一个哦
            if (X >= M / n + 1) {
                m = M;
                X = X - M / n - 1;
            }
            else {
                /*m = X * n;
                X = 0;*/
                break;
            }
        }
        //开始战斗，提升战斗力
        n += m / n;
        //体力变成0
        m = 0;
    }
    cout << n;
    return 0;
}

027:数字统计

#include <iostream>
using namespace std;
int main()
{
  int A,B;
  int n=0;
  cin >> A >> B;
  for (;A<=B;A++)
  {
    int i=A;
    while(i>0)
    {
      if(i%10==2) n++;
      i/=10;
    }
  }
  cout << n << endl;
  return 0;
}

028:与指定数字相同的数的个数

# include<iostream>
using namespace std;

int main()
{
    int N;
    cin >> N;
    int M[110];
    for (int i = 0; i < N; ++i) {
        cin >> M[i];
    }
    int m, geshu=0;
    cin >> m;
    for (int i = 0; i < N; ++i){
        if (M[i] == m)  geshu++;
        }
    cout << geshu;

    return 0;
}

029:陶陶摘苹果

# include<iostream>
using namespace std;

int main()
{
    int height[10];
    for (int i = 0; i < 10; i++) {
        cin >> height[i];

    }
    int taotao, geshu=0;
    cin >> taotao;
    taotao += 30;
    for (int i = 0; i < 10; i++) {
        if (height[i] <= taotao) geshu++;
    }
    cout << geshu;
    return 0;
}

030:年龄与疾病

# include<iostream>
using namespace std;

int main()
{
    int n;
    cin >> n;
    int a[101];
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    int zu0_18 = 0, zu19_35=0, zu36_60=0, zu61_=0;
    for (int i = 0; i < n; i++) {
        if (a[i] >= 0 && a[i] <= 18) zu0_18++;
        else if (a[i] >= 19 && a[i] <= 35) zu19_35++;
        else if (a[i] >= 35 && a[i] <= 60) zu36_60++;
        else if (a[i] >= 61) zu61_++;
    }
    float zu1, zu2, zu3, zu4;
    zu1 = float(zu0_18) / n * 100;
    zu2 = float(zu19_35) / n * 100;
    zu3 = float(zu36_60) / n * 100;
    zu4 = float(zu61_) / n * 100;
    printf("%.2f", zu1);
    printf("%%\n");
    printf("%.2f",  zu2);
    printf("%%\n");
    printf("%.2f",  zu3);
    printf("%%\n");
    printf("%.2f",  zu4);
    printf("%%\n");
}

031:校门外的树

# include<iostream>
using namespace std;
//搞一个数组，存放所有马路上的树，有树为1.移走为0
int main()
{
    int L, M;
    cin >> L >> M;
    int s[10001];
    for (int i = 0; i <= L; i++) {
        s[i] = 1;
    }
    int low, high;
    for (int i = 0; i < M; i++) {
        cin >> low >> high;
        for (int j = low; j <= high; j++) {
            s[j] = 0;
        }
    }
    int geshu = 0;
    for (int i = 0; i <= L; i++) {
        if (s[i]) geshu++;
    }
    cout << geshu;
    return 0;
}

032:计算鞍点

# include<iostream>
using namespace std;
int s[5][5];
int main()
{
    for (int i = 0; i < 5; i++) {
        for (int j = 0; j < 5; j++) {
            cin >> s[i][j];
        }
    }
    int zuida, zuixiao, zhaodao = 0;
    for (int i = 0; i < 5; i++) {
        zuida = s[i][0];
        int zuida_j = 0;
        for (int j = 1; j < 5; j++) {
            if (s[i][j] > zuida) {
                zuida = s[i][j];
                zuida_j = j;
            }
        }
        zuixiao = s[0][zuida_j];
        int zuixiao_i = 0;
        for (int m = 1; m < 5; m++) {
            if(s[m][zuida_j]<zuixiao){
                zuixiao = s[m][zuida_j];
                zuixiao_i = m;
            }
        }
        if (zuida == zuixiao) {
            cout << i+1 << " " << zuida_j+1 << " " << zuida;
            zhaodao = 1;
        }
    }
    if (zhaodao == 0)  cout << "not found";
    return 0;
}

033:图像模糊处理

# include<iostream>
#include<math.h>
using namespace std;
int p[110][110], p1[110][110];
int main()
{
    int n, m;
    cin >> n >> m;
    for (int i=0; i < n; i++) {
        for (int j=0; j < m; j++) {
            cin >> p[i][j];
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (i == 0 || j == 0||i==n-1||j==m-1) {
                p1[i][j] = p[i][j];
            }
            else
            p1[i][j] = round(float(p[i - 1][j] + p[i][j - 1] + p[i + 1][j] + p[i][j + 1]+p[i][j]) / 5);
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cout << p1[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}

034:矩阵转置

#include <iostream>
using namespace std;
#define N 100
int n,m;
int a[N][N];
int main(){
	scanf("%d %d",&n,&m);
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			scanf("%d",&a[i][j]);
		}
	}
	for(int i=0;i<m;i++){
		for(int j=0;j<n;j++){	//矩阵转置后行数和例数也随之转置
			printf("%d ",a[j][i]);
		}
		printf("\n");
	}
	return 0;
}

035:Pell数列

# include<iostream>
# include<math.h>
using namespace std;
int a[101], p[1000010];

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    p[1] = 1;
    p[2] = 2;
    for (int i = 3; i < 1000010; i++) {
        p[i] = (2 * p[i - 1] + p[i - 2]) % 32767;
    }
    for (int i = 0; i < n; i++) {
        cout << p[a[i]] << endl;
    }
    
    return 0;
}

036:求最大公约数问题

# include<iostream>
# include<math.h>
using namespace std;


int main()
{
    int m, n, temp;
    cin >> m >> n;
    if (m > n) {
        temp = m;
        m = n;
        n = temp;
    }
    //现在确保m是较小的那个数了
    int yueshu=0;
    for (int i = 1; i <= m; i++) {
        if (m % i == 0) {
            if (n % i == 0) {
                yueshu = i;
            }
        }
    }
    cout << yueshu;
    return 0;

}

037:编程填空：第i位替换

#include <iostream>
using namespace std;

int bitManipulation1(int n, int m, int i) {
return ((1 << (i)) & m) + ((~(1 << (i))) & n);
}

int main() {
	int n, m, i, t;
	cin >> t;
	while (t--) { 
		cin >> n >> m >> i;
		cout << bitManipulation1(n, m, i) << endl;
	}
	return 0;
}

038:编程填空：第i位取反

#include <iostream>
using namespace std;

int bitManipulation2(int n, int i) {
return (1 << i) ^ n;
}

int main() {
	int t, n, i;
	cin >> t;
	while (t--) {
		cin >> n >> i;
		cout << bitManipulation2(n, i) << endl;
	}
	return 0;
}

039:编程填空：左边i位取反

#include <iostream>
using namespace std;

int bitManipulation3(int n, int i) {
return (-1 << (32-i)) ^ n;
}

int main() {
	int t, n, i;
	cin >> t;
	while (t--) {
		cin >> n >> i;
		cout << bitManipulation3(n, i) << endl;
	}
	return 0;
}

040:统计数字字符个数

#include <iostream>
using namespace std;

char line[260];
int geshu=0;
int main() {
	cin.getline(line, 260);
	for (int i = 0; line[i]; ++i) {
		if (line[i] >= '0' && line[i] <= '9')
			geshu++;
	}
	cout << geshu;
	return 0;
}

041:找第一个只出现一次的字符

#include <iostream>
using namespace std;
char shuru[100000];
int zimu[26];
int cunzai = 0, chongfu = 0;
int main() {
	cin >> shuru;
	for (int i = 0; shuru[i]; ++i) {
		chongfu = 0;
		if (shuru[i] != 'H') {
			for (int j = i+1; shuru[j]; ++j) {
				if (shuru[j] == shuru[i]) {
					shuru[j] = 'H';
					chongfu = 1;
				}
			}
			if (chongfu == 0) {
				cout << shuru[i];
				cunzai = 1;
				break;
			}
		}
	}
	if (cunzai == 0) {
		cout << "no";
	}
	return 0;
	
}

042:石头剪子布

#include <iostream>
#include <cstring>
using namespace std;
int N;
char p1[10], p2[10];
int n[110];
int main() {
	cin >> N;
	for (int i=0;i<N;++i){
		cin >> p1 >> p2;
		if (strcmp(p1, "Rock")==0) {
			if (strcmp(p2, "Rock") == 0) n[i]=0;
			if (strcmp(p2, "Scissors") == 0) n[i]=1;
			if (strcmp(p2, "Paper") == 0) n[i] = 2;
		}
		if (strcmp(p1, "Scissors")==0) {
			if (strcmp(p2, "Rock") == 0) n[i] = 2;
			if (strcmp(p2, "Scissors") == 0) n[i] = 0;
			if (strcmp(p2, "Paper")==0) n[i] = 1;
		}
		if (strcmp(p1, "Paper")==0) {
			if (strcmp(p2, "Rock") == 0) n[i] = 1;
			if (strcmp(p2, "Scissors") == 0) n[i] = 2;
			if (strcmp(p2, "Paper")==0) n[i] = 0;
		}
	}
	for (int i = 0; i < N; i++) {
		if (n[i] == 0) cout << "Tie\n";
		if (n[i] == 1) cout << "Player1\n";
		if (n[i] == 2) cout << "Player2\n";
	}
	return 0;
	
}

043:最长最短单词

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int main()
{
    char s[10000];
    int len;
    int sum = 0, max_len = 0, min_len = 9999;
    int max_i=0, min_i=0;
    int i;
    cin.getline(s,10000);
    len = strlen(s);//字符长度
    s[len] = ' ';//在字符串后加以空格，方便判定

    for (i = 0; i < len+1; i++)
    {
        if (s[i] != ' ' && s[i] != ',')	sum++;//若不是空格或逗号，累加单词长度
        else if (sum > 0)//若是空格或逗号
        {
            if (sum > max_len)
            {
                max_len = sum;//存储目前最长的单词长度
                max_i = i - sum;//记录最长单词的位置
            }
            if (sum < min_len)
            {
                min_len = sum;//存储目前最短的单词长度
                min_i = i - sum;//记录最短单词的位置
            }
            sum = 0;//计数器归零
        }
    }
    for (i = max_i; i <= max_i + max_len - 1; i++) 
        cout << s[i];//输出最长单词
    cout << endl;
    for (i = min_i; i <= min_i + min_len - 1; i++)
        cout << s[i];//输出最短单词
    return 0;
}

044:密码翻译

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
char line[90];
int main()
{
    cin.getline(line, 85);
    int len = strlen(line);
    for (int i = 0; i < len; i++) {
        if (line[i] == 'z') line[i] = 'a';
        else if (line[i] == 'Z') line[i] = 'A';
        else if ((line[i] >= 'a' && line[i] < 'z') ||
            (line[i] >= 'A' && line[i] < 'Z'))
            line[i] += 1;
    
    }
    for (int i = 0; i < len; i++) {
        cout << line[i];
    }
    return 0;
}

045:指针练习：输出Hello

#include <iostream>
using namespace std;
int main() {
	char s[] = "Hello";  
	char * p;
	for(
p=s;*p;p++
)
		cout << * p ;
	return 0;
}

046:指针练习:输出Tesla

#include <iostream>
using namespace std;
void Print(const char * p1, const char * p2) 
{  
	for(
;p1<p2;p1++
) 	
		cout << * p1;
}
int main()  
{
	const char * s = "Tesla123";
	Print(s,s+5);
	cout << endl;
	Print(s,s+3);
	cout << endl;
	
	return 0;
}

047:指针练习：ForEach

#include <iostream>
using namespace std;

void ForEach(void * a, int width, int num,
void (*f)(void *p)
)

{
	for(int i = 0;i < num; ++i) 
		f((char*)a+width*i);
}

void PrintSquare(void * p)
{
	int * q = (int*)p;
	int n = *q;
	cout << n * n << ",";
}
void PrintChar(void * p) {
	char * q = (char*)p;
	cout << *q << ",";
}
int main()
{
	int a[5] = {1,2,3,4,5};
	char s[] = "hello!";
	ForEach(a,sizeof(int),5,PrintSquare); 
	cout << endl;
	ForEach(s,sizeof(char),6,PrintChar);
	return 0;
}

048:指针练习：Memcpy之一

#include <iostream>
using namespace std;
void Memcpy(char * src,char * dest,int n)
{
for (int i = 0; i < n; i++) {
		*(dest + i) = *(src + i);
	}
}
int Strlen(char * s)
{	
	int i;
	for( i = 0; s[i]; ++i);
	return i;
}
int main()  
{
	int a;
	char s1[30];
	char s2[30];
	int t;
	cin >> t;
	for(int i = 0;i < t; ++i) {
		cin >> a;
		int b = 99999999;
		Memcpy((char*)&a,(char *) &b,sizeof(int));
		cout << b << endl;
	}
	for(int i = 0;i < t; ++i) {
		cin >> s1;
		Memcpy(s1,s2,Strlen(s1)+1);
		cout << s2 << endl;
	}
	return 0;
}

049:指针练习：double

#include <iostream>
using namespace std;

void Double(int * p, int n)
{
	for(int i = 0;i < n; ++i)
		p[i] *= 2;
}


int main()
{
	int a[3][4] = { { 1,2,3,4},{5,6,7,8},
					{ 9,10,11,12 } };
	
	Double(
a[1], 6
);
	for(int i = 0;i < 3; ++i) {
		for(int j = 0; j < 4; ++j)
			cout << a[i][j] << ",";
		cout << endl; 
	}
	
	return 0;
}

050:指针练习：Memcpy之二

#include <iostream>
using namespace std;
void Memcpy( void * src, void * dest, int size)
{
char temp[100];
	for (int i = 0; i < size; i++) {
		temp[i] = *((char*)src + i);
	}
	for (int i = 0; i < size; i++) {
		*((char *)dest+i) = temp[i];
	}
}

void Print(int * p,int size)
{
	for(int i = 0;i < size; ++i)
		cout << p[i] << ",";
	cout << endl;
}

int main()
{
	int a[10];
	int n;
	cin >> n;
	for(int i = 0;i < n; ++i)
		cin >> a[i];
	int b[10] = {0};
	Memcpy(a,b,sizeof(a));
	Print(b,n);
	
	int c[10] = {1,2,3,4,5,6,7,8,9,10};
	Memcpy(c,c+5,5*sizeof(int)); //将c的前一半拷贝到后一半 
	Print(c,10);

	char s[10] = "123456789";
	Memcpy(s+2,s+4,5); //将s[2]开始的5个字符拷贝到s[4]开始的地方 
	cout << s << endl;
	
	char s1[10] = "123456789";
	Memcpy(s1+5,s1+1,4); //将s1[5]开始的4个字符拷贝到s1[1]开始的地方 
	cout << s1 << endl;
	
	
	return 0;
}

051:指针练习：MyMax

#include <iostream>
using namespace std;
char* MyMax(void* a, int s, int n, int (*f)(void* n1, void* n2)) {
	char* zuida = (char*)a;
	for (int i = 0; i < n; ++i) {
		if ((f(zuida, (char*)a + s*i))<0) {
			zuida = (char*)a + s*i;
		}
	}
	return zuida;
}
int Compare1(void * n1,void * n2)
{
	int * p1 = (int * )n1;
	int * p2 = (int * )n2;
	return ((*p1)%10) - ((*p2)%10);
}
int Compare2(void * n1,void * n2)
{
	int * p1 = (int * )n1;
	int * p2 = (int * )n2;
	return *p1 - *p2;
}
#define eps 1e-6
int	Compare3(void * n1,void * n2)
{
	float * p1 = (float * )n1;
	float * p2 = (float * )n2;
	if( * p1 - * p2 > eps)
		return 1;
	else if(* p2 - * p1 > eps)
		return -1;
	else
		return 0; 
}

int main()
{
	int t;
	int a[10];
	float d[10];
	cin >> t;
	while(t--) {
		int n;
		cin >> n;
		for(int i = 0;i < n; ++i)
			cin >> a[i];
		for(int i = 0;i < n; ++i)
			cin >> d[i];
		int * p = (int *) MyMax(a,sizeof(int),n,Compare1);
		cout << * p << endl;
		p = (int *) MyMax(a,sizeof(int),n,Compare2);
		cout << * p << endl;
		float * pd = (float * )MyMax(d,sizeof(float),n,Compare3);
		cout << * pd << endl;
	}
	return 0;
}

052:指针练习：指向指针的指针

#include <iostream>
using namespace std;
int main()
{
	int x,y,z;
	x = 10;
	y = 20;
	z = 30;
	
	int * a[3]  = { &x, &y,&z};
	for(
int** p = a;
p < a + 3; ++p) 
			cout<< * (*p) << endl;
	return 0;
	
}

053:指针练习：SwapMemory

#include <iostream>
using namespace std;
void SwapMemory(void * m1,void * m2, int size)
{

	// 交换m1和m2，内存大小是size
	char temp;
	for (int i = 0; i < size; ++i) {
		temp = *((char*)m1 + i);
		*((char*)m1 + i) = *((char*)m2 + i);
		*((char*)m2 + i) = temp;
	}

}

void PrintIntArray(int * a,int n)
{
	for(int i = 0;i < n; ++i)
		cout << a[i] << ",";
	cout << endl;
}

int main()
{
	int a[5] = {1,2,3,4,5};
	int b[5] = {10,20,30,40,50};
	SwapMemory(a,b,5 * sizeof(int));
	PrintIntArray(a,5);
	PrintIntArray(b,5);
	char s1[] = "12345";
	char s2[] = "abcde";
	SwapMemory(s1,s2,5);
	cout << s1 << endl;
	cout << s2 << endl;
	return 0;
}

054:成绩排序

#include <iostream>
using namespace std;
struct student {
	string name;
	int grade;
};
student s[20];
int main() {
	int n;
	cin >> n;
	for(int i=0;i<n;++i){
		// 将输入的n组数据存在一个数组中
		cin >> s[i].name;
		cin >> s[i].grade;
	}
	// 排序
	for (int i = 0; i < n - 1; ++i) {
		int tmpMax = i;
		for (int j = i + 1; j < n; ++j) {
			if (s[j].grade > s[tmpMax].grade)
				tmpMax = j;
			else if (s[j].grade == s[tmpMax].grade) {
				if (s[j].name < s[tmpMax].name) {
					tmpMax = j;
				}
			}
		}
		student tmp = s[i];
		s[i] = s[tmpMax];
		s[tmpMax] = tmp;

		

	}
	// 排好了，输出
	for (int i = 0; i < n; ++i) {
		cout << s[i].name << " " << s[i].grade << endl;
	}



}

055:分数线划定

#include <iostream>
using namespace std;
struct xuanshou {
	string xuhao;
	int grade;
};
xuanshou x[5005];
int main() {
	int n, m;
	cin >> n >> m;
	// 输入选手的笔试分数
	for (int i = 0; i < n; ++i) {
		cin >> x[i].xuhao;
		cin >> x[i].grade;
	}
	
	// 排序，选择排序
	for (int i = 0; i < n - 1; ++i) {
		int tmpMax = i;
		for (int j = i + 1; j < n; ++j) {
			if (x[j].grade > x[tmpMax].grade)
				tmpMax = j;
			else if (x[j].grade == x[tmpMax].grade) {
				if (x[j].xuhao < x[tmpMax].xuhao)
					tmpMax = j;
			}

		}
		xuanshou tmp = x[i];
		x[i] = x[tmpMax];
		x[tmpMax] = tmp;
	}
	// 计算进入笔试的人数
	int geshu = m * 1.5;
	for (int i = geshu; i < n; ++i) {
		if (x[i].grade == x[geshu - 1].grade)
			geshu++;
	}
	// 输出
	cout << x[geshu - 1].grade << " ";
	cout << geshu << endl;
	for (int i = 0; i < geshu; ++i) {
		cout << x[i].xuhao << " ";
		cout << x[i].grade << endl;
	}

}

056:病人排队

#include <iostream>
using namespace std;
struct bingren {
	string id;
	int age;
	int xuhao;
};
bingren x[5005];
int main() {
	int n;
	cin >> n;
	// 输入病人id和年龄
	for (int i = 0; i < n; ++i) {
		cin >> x[i].id;
		cin >> x[i].age;
		x[i].xuhao = i;
	}
	
	// 排序，选择排序
	for (int i = 0; i < n - 1; ++i) {
		int tmpMin = i;
		for (int j = i + 1; j < n; ++j) {
			// 新病人是老年人
			if(x[j].age>=60){
				// 在位病人是老年人
				if (x[tmpMin].age >= 60) {
					// 新病人的年纪比较大
					if (x[j].age > x[tmpMin].age) {
						tmpMin = j;
					}
					// 年纪一样大
					else if (x[j].age == x[tmpMin].age) {
						// 新病人的排号靠前
						if (x[j].xuhao < x[tmpMin].xuhao) {
							tmpMin = j;
						}
					}
				}
				// 在位病人是年轻人
				else {
					tmpMin = j;
				}
			}
			// 新病人是年轻人
			else {
				//在位病人也是年轻人
				if (x[tmpMin].age < 60) {
					// 新病人序号靠前
					if (x[j].xuhao < x[tmpMin].xuhao) {
						tmpMin = j;
					}
				}
			}
		}
		bingren tmp = x[i];
		x[i] = x[tmpMin];
		x[tmpMin] = tmp;
	}
	
	
	// 输出
	for (int i = 0; i < n; ++i) {
		cout << x[i].id << endl;
	}
	return 0;
}

057:mysort

#include <iostream>
using namespace std;
struct A {
	int nouse1;
	int nouse2;
	int n;
};

void mysort(void* a, int n, int w, int(*f)(const void* e1, const void* e2))
{
	char* s = (char*)a;
	for (int i = 0; i < n - 1; i++) {
		for (int j = i + 1; j < n; j++) {
			char* p1 = (char*)a + i * w;
			char* p2 = (char*)a + j * w;
			if (f(p1, p2) > 0) {
				for (int k = 0; k < w; k++) {
					char tem = p1[k];
					p1[k] = p2[k];
					p2[k] = tem;
				}
			}
		}
	}
}
int MyCompare1( const void * e1,const void * e2) 
{
	int * p1 = (int * ) e1;
	int * p2 = (int * ) e2;
	return * p1 - * p2;
}
int MyCompare2( const void * e1,const void * e2) 
{
	int * p1 = (int * ) e1;
	int * p2 = (int * ) e2;
	if( (* p1 %10) - (* p2 % 10))
		return (* p1 %10) - (* p2 % 10);
	else
		return * p1 - * p2;
}
int MyCompare3( const void * e1,const void * e2) 
{
	A * p1 = (A*) e1;
	A * p2 = (A*) e2;
	return p1->n - p2->n;
}
int a[20];
A b[20];
int main ()
{	
	int n;
	while(cin >> n) {
		for(int i = 0;i < n; ++i) {
			cin >> a[i];
			b[i].n = a[i];
		}
		mysort(a,n,sizeof(int),MyCompare1);
		for(int i = 0;i < n; ++i) 
			cout << a[i] << "," ;
		cout << endl;
		mysort(a,n,sizeof(int),MyCompare2);
		for(int i = 0;i < n; ++i) 
			cout << a[i] << "," ;
		cout << endl;
		mysort(b,n,sizeof(A),MyCompare3);
		for(int i = 0;i < n; ++i) 
			cout << b[i].n << "," ;
		cout << endl;
	}
	return 0;
}

058:从字符串中取数

#include <iostream>
#include <iomanip>
using namespace std;
double GetDoubleFromString(char * str)
{

	// 在此处补充你的代码
	static char* p;
	if (str)
		p = str;
	double num = 0;
	while (*p && !(*p >= '0' && *p <= '9'))
		++p;   // 跳过不是数字的字符
	if (*p == 0)   // 如果跳完了，就代表结束了
		return NULL;
	// 把连续的数字字符变成浮点数的整数部分
	while (*p >= '0' && *p <= '9') {
		num = num * 10 + *p - '0';
		++p;
	}
	// 遇到小数点
	if (*p == '.') {
		++p;
		double i = 10;
		// 把小数点后面的数字字符变成浮点数的小数部分
		while (*p >= '0' && *p <= '9') {
			num += (*p - '0') / i;
			++p;
			i *= 10;
		}
	}
	return num;



}

int main()
{
	char line[300];
	while(cin.getline(line,280)) {
		double n;
		n = GetDoubleFromString(line);
		while( n > 0) {
			cout << fixed << setprecision(6) << n << endl;
			n = GetDoubleFromString(NULL);
		}
	}
	return 0;
}

059:sort简单题

#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
	int a[8] = {6,5,14,23,2,9,87,10 };
	sort(
a+1, a+7, greater<int>()
);
	for(int i = 0;i < 8; ++i)
		cout << a[i] << "," ; 
	return 0;
}

060:还是sort简单题

#include <iostream>
#include <algorithm>
#include <cmath>
using namespace std;

struct Point{
	int x;
	int y;
};
// 在此处补充你的代码
struct Rule1
{
	bool operator()(const int& a1, const int& a2) const {
		if (a1 % 10 != a2 % 10) {
			return a1 % 10 < a2 % 10;
		}
		else {
			return a1 > a2;
		}
	}
};
struct Rule2
{
	bool operator()(const Point& a1, const Point& a2) const {
		int l1 = a1.x * a1.x + a1.y * a1.y;
		int l2 = a2.x * a2.x + a2.y * a2.y;
		if (l1 != l2) {
			return l1 < l2;
		}
		else {
			if (a1.x != a2.x)
				return a1.x < a2.x;
			else
				return a1.y < a2.y;
		}
	}
};
int main()
{
	int a[8] = {6,5,55,23,3,9,87,10 };
	sort(a,a+8,Rule1());
	for(int i = 0;i < 8; ++i)
		cout << a[i] << "," ; 
	cout << endl;
	Point ps[8] = {{1,0},{0,1},{0,-1},{-1,0},{1,-1},{1,1},{2,0},{-2,0} } ;
	sort(ps,ps+8,Rule2());
	for(int i = 0;i < 8; ++i)
		cout << "(" << ps[i].x << "," << ps[i].y << ")"; 
	return 0;
}

061:Set

#include <iostream>
#include <set>
#include <string>
#include <iterator>

using namespace std;

int main()
{
    multiset<int> mset;
    set<int> mm;
    char commend[5];
    int i, n, num, amount;
    multiset<int>::iterator it;
    cin >> n;
    for (i = 0; i < n; i++)
    {
        cin >> commend >> num;
        switch (commend[1])
        {
        case 'd':
            mset.insert(num);
            mm.insert(num);
            cout << mset.count(num) << endl;
            break;
        case 'e':
            cout << mset.count(num) << endl;
            mset.erase(num);
            break;
        case 's':
            if (mm.find(num) == mm.end())
                cout << "0 0" << endl;
            else
            {
                cout << "1 ";
                cout << mset.count(num) << endl;
            }
            break;
        }
    }
    return 0;
}

062:热血格斗场

#include <iostream>
#include <map>
#include <string>
#include <iterator>
using namespace std;
// 保证输入没有战斗力相同的，那么就可以用map保存
struct Ren {
	int zhanli;
	int id;
};
typedef map<int, int> MP;
int main() {
	int n;
	MP mp;
	scanf("%d", &n);
	// 把老板加进去
	Ren ren;
	ren.id = 1;
	ren.zhanli = 1000000000;
	mp.insert(make_pair(ren.zhanli, ren.id));
	while (n--) {
		scanf("%d%d", &ren.id, &ren.zhanli);
		MP::iterator di = mp.lower_bound(ren.zhanli);
		MP::iterator gao;
		if (di != mp.begin()) {
			// 新加入的人不是最弱的
			if (di != mp.end()) {
				// 新加入的人是中间的
				gao = di;
				di--;
				
				if (ren.zhanli - di->first == gao->first - ren.zhanli) {
					//上下差距一样
					printf("%d %d\n", ren.id, di->second);
				}
				else if (ren.zhanli - di->first < gao->first - ren.zhanli) {
					// 下面差距小
					printf("%d %d\n", ren.id, di->second);
				}
				else {
					// 上面差距小
					printf("%d %d\n", ren.id, gao->second);
				}
			}
			else {
				// 新加入的人是最强的
				// 和目前最强的人打
				di--;
				printf("%d %d\n", ren.id, di->second);
			}

		}
		else {
			// 新加入的人是最弱的
			// 和目前最弱的人打
			printf("%d %d\n", ren.id, di->second);
		}
		// 整完之后把这个人加进去
		mp.insert(make_pair(ren.zhanli, ren.id));
	}
	return 0;
}

063:冷血格斗场

#include <iostream>
#include <algorithm>
#include <map>
using namespace std;

int main()
{
	int n, value, id;
	scanf("%d", &n);
	map<int, int> member;
	member[1000000000] = 1;
	for (int i = 1; i <= n; i++) {
		scanf("%d %d", &id, &value);
		auto it = member.lower_bound(value);      // 返回最小的大于等于value的迭代器 
		if (it == member.end())
			--it;
		if (it == member.begin()) {
			printf("%d %d\n", id, it->second);
		}
		else {
			auto jt = it;
			jt--;
			if (value - jt->first < it->first - value)
				printf("%d %d\n", id, jt->second);
			else if (value - jt->first > it->first - value)
				printf("%d %d\n", id, it->second);
			else {
				if (jt->second < it->second)
					printf("%d %d\n", id, jt->second);
				else
					printf("%d %d\n", id, it->second);
			}
		}
		it = member.find(value);
		if (it == member.end() || it->second > id)
			member[value] = id;
	}


}

悦读

道可道，非常道；名可名，非常名。 无名，天地之始，有名，万物之母。 故常无欲，以观其妙，常有欲，以观其徼。 此两者，同出而异名，同谓之玄，玄之又玄，众妙之门。

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