C语言实现归并排序
2路归并排序算法
1.定义动态数组
typedef struct {
int *data;
} DSqList;
2.初始化动态数组
void InitDSqList(DSqList &L, int len) {
L.data = (int *) malloc(len * sizeof(int));
}
3.归并操作
void Merge(int A[], int low, int mid, int high) {
int i, j, k;
for (int p = low; p <= high; ++p) {
B.data[p] = A[p];
}
for (i = low, j = mid + 1, k = i; i <= mid && j <= high; ++k) {
if (B.data[i] <= B.data[j])
A[k] = B.data[i++];
else
A[k] = B.data[j++];
}
while (i <= mid)
A[k++] = B.data[i++];
while (j <= high)
A[k++] = B.data[j++];
}
4.归并排序算法实现
void MergeSort(int A[], int low, int high) {
if (low < high) {
int mid = (low + high) / 2;
MergeSort(A, low, mid);
MergeSort(A, mid + 1, high);
Merge(A, low, mid, high);
}
}
项目完整代码
#include <stdio.h>
#include <stdlib.h>
typedef struct {
int *data;
} DSqList;
DSqList B;
void InitDSqList(DSqList &L, int len) {
L.data = (int *) malloc(len * sizeof(int));
}
void Merge(int A[], int low, int mid, int high) {
int i, j, k;
for (int p = low; p <= high; ++p) {
B.data[p] = A[p];
}
for (i = low, j = mid + 1, k = i; i <= mid && j <= high; ++k) {
if (B.data[i] <= B.data[j])
A[k] = B.data[i++];
else
A[k] = B.data[j++];
}
while (i <= mid)
A[k++] = B.data[i++];
while (j <= high)
A[k++] = B.data[j++];
}
void MergeSort(int A[], int low, int high) {
if (low < high) {
int mid = (low + high) / 2;
MergeSort(A, low, mid);
MergeSort(A, mid + 1, high);
Merge(A, low, mid, high);
}
}
int main() {
int A[] = {49, 38, 65, 97, 76, 13, 27};
int len = sizeof(A) / sizeof(int);
InitDSqList(B, len);
MergeSort(A, 0, len - 1);
printf("归并排序后的结果为:");
for (int i = 0; i < len; ++i) {
printf("%d ", A[i]);
}
return 0;
}
运行效果图
int A[] = {49, 38, 65, 97, 76, 13, 27};