PAT T1015 Letter-moving Gam

双下标法找最长公共子序列（不能删除字符）

#include<bits/stdc++.h>
using namespace std;
const int maxn=1014;
string s;
string t;
int main () {
    cin>>s>>t;
    int maxLength=0;
    int st,ed;
    for (int i=0;i<s.length();i++) {
        st=i;
        ed=0;
        while (st<s.length()&&ed<s.length()) {
            if (s[ed]==t[st]) st++;
            ed++;
        }
        maxLength=max(maxLength,st-i);
    }
    printf ("%d",s.length()-maxLength);
    return 0;
}