209. 长度最小的子数组

class Solution {
public:
    int minSubArrayLen(int target, vector<int>& nums) {
     int ant=0,mi=1000005;
     int q[100009];int hh=0,tt=-1;
     for(int i=0;i<nums.size();i++)
     {
        q[++tt]=nums[i];
        ant+=nums[i];
        while(hh<=tt&&ant>=target)
        {
            mi=min(mi,tt-hh+1);
            ant-=q[hh];
            hh++;
        }

     }
     if(mi==1000005)return 0;
     return mi;
    }
};

1234. 替换子串得到平衡字符串

class Solution {
public:
    int balancedString(string s) {
       unordered_map<char,int> m;
       int mi=100005;
       for(auto i:s)m[i]++;
       int l=s.size(),cl=l/4;
       if(m['Q']==cl&&m['W']==cl&&m['E']==cl&&m['R']==cl)
        return 0;

        for(int i=0,j=0;i<l;i++)
        {
            m[s[i]]--;
            while(m['Q']<=cl&&m['W']<=cl&&m['E']<=cl&&m['R']<=cl)
            {
                mi=min(mi,i-j+1);
                m[s[j]]++;
                j++;
            }
        }
        return mi;
    }
};

1574. 删除最短的子数组使剩余数组有序

class Solution {
public:
    int findLengthOfShortestSubarray(vector<int>& arr) {
        int n=arr.size(),r=n-1;
        while(r&&arr[r-1]<=arr[r])r--;
        if(r==0)return 0;
        int ant=r;
        for(int i=0;i==0||arr[i-1]<=arr[i];i++)
        {
            while(r<n&&arr[r]<arr[i])r++;
            ant=min(ant,r-i-1);
        }
        return ant;
    }
};

面试题 17.18. 最短超串

class Solution {
public:
    vector<int> shortestSeq(vector<int>& big, vector<int>& small) {
       int lb=big.size(),ls=small.size();
       int ant=100005;vector<int> answer;
       if(ls>lb)return {};
       unordered_map<int,int> ms;
       int lendif=0;
       for(int i=0;i<ls;i++)
       {
        ms[small[i]]++;
        lendif++;
       }
       
      for(int i=0,j=0;i<lb;i++)
      {
        if(ms.find(big[i])!=ms.end()&&--ms[big[i]]>=0)--lendif;
        while(lendif==0)
        {
            if(i-j+1<ant)
            {
                ant=i-j+1;
               answer={j,i};
            }
            if(ms.find(big[j])!=ms.end()&&++ms[big[j]]>0)++lendif;
            ++j;
        }

      } 

       return answer;
    }
};