滑动窗口+substr+map——leetcode30

class Solution {
public:
    
    vector<int>ans;
    unordered_map<string,int> cnt;
    int n,k,len;

    vector<int> findSubstring(string s, vector<string>& words) {
        if(words.size()==0)return ans;
        n=words.size();
        k=words[0].size();
        len=s.size();
        if(n*k>s.size())return ans;

        for(auto s:words)cnt[s]++;
        
        for(int i=0;i<k;i++){
            int tot=0;
            unordered_map<string,int> mp;
            int l=i,r=i;
            while(r+k-1<=len-1){
                string tmp=s.substr(r,k);
                if(cnt[tmp]==0){
                    r+=k;l=r;tot=0;
                    mp.clear();continue;
                }else {
                    tot++;
                    mp[tmp]++;
                    r+=k;
                    while(cnt[tmp]<mp[tmp]){
                        string t=s.substr(l,k);
                        mp[t]--;tot--;
                        l+=k;
                    }
                }
                if(tot==n)ans.push_back(l);
            }
        }

        return ans;
    }
};