代码随想录：判断子序列

class Solution {
public:
    bool isSubsequence(string s, string t) {
        if(s.length()==0)return true;
        int target = 0;
        for(int i = 0;i<t.length();i++){
            if(t[i]==s[target]){
                target++;
            }
            if(target==s.length())return true;
        }
        return false;
    }
};