No.140 - LeetCode567

class Solution {
public:
    bool judge(vector<int>& A,vector<int>& B){
        for(int i=0;i<26;i++) if(A[i] != B[i]) return false;
        return true;
    }
    bool checkInclusion(string s1, string s2) {
        int N = s2.length();
        int L = s1.length();
        if(L > N) return false;
        vector<int> A(30),B(30);
        for(int i=0;i<L;i++){
            A[s1[i]-'a'] ++;
            B[s2[i]-'a'] ++;
        } 
        if(judge(A,B)) return true;
        for(int i=L;i<N;i++){
            B[s2[i]-'a'] ++;
            B[s2[i-L]-'a']--;
            if(judge(A,B)) return true;
        }
        return false;
    }
};