The longest child sequence of the 2019 Blue Bridge Cup

Topic link ：

link : The longest subsequence .

Ideas

As soon as you see the longest subsequence, you can think of using the double pointer algorithm to solve it , The subject is very simple , Just simulate it .

C++ Code

#include<bits/stdc++.h>
using namespace std;
int main(){
    
    string s1, s2;
    cin >> s1 >> s2;
    int len = 0;
    for(int i = 0, j = 0; i < s1.size(); i++){
    
        if(s1[i] == s2[j]){
    
            j++;
            len++;
        }
    }
    cout << len;
    return 0;
}