uva10340

题目：判断a串是不是b串的子串。
代码:

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
using namespace std;
string s1,s2;
int main() {

    while(cin>>s1>>s2) {

        int flag = 0;
        bool change;
        for(int i=0; i<s1.size(); i++) {
            change = false;
            for(int j=flag; j<s2.size(); j++) {

                if(s1[i]==s2[j]) {
                    flag = j+1;
                    change = true;
                    break;
                }
            }
            if(!change) break;
        }
        if(change) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}