Codeforces Round #253 (Div. 2), problem: (B)【字符串匹配】

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <math.h>
 4 #include <iostream>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 int main(){
 9     int i, j, k, t, n;
10     int num, flag, ans;
11     char a[300];
12     scanf("%s",a);
13     scanf("%d",&k);
14     int len = strlen(a);
15     num = len + k;
16     num /= 2;
17     flag = 0;
18     for(n = num; n > 0; --n){
19         for(j = 0; j < len; ++j){
20             i = j;
21             while(i < j + n && i <(len + k - n)){
22                 if((i + n) >= len){
23                     ++i;
24                     continue;
25                 }
26                 if(a[i] == a[i + n]){
27                     ++i;
28                     continue;
29                 }
30                 else    break;
31             }
32 
33             if(i == j + n){
34                 flag = 1;
35                 break;
36             }
37         }
38         if(flag)    break;
39     }
40     printf("%d\n",n * 2);
41     return 0;
42 }