【Leetcode每日刷题3】

双指针法

class Solution {
public:
    bool isSubsequence(string s, string t) {
        int lenS = s.size(); 
        int lenT = t.size();
        if(lenS == 0){
            return true;
        }
        if(lenT == 0){
            return false;
        }
        int i = 0, j = 0;
        while(i < lenT){
            if(t[i] == s[j]){
                j ++;
            }
            i ++;
        }
        if(j == lenS){
            return true;
        }
        return false;


    }
};