POJ 3080 Blue Jeans

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <climits>
 7 #include <vector>
 8 #include <queue>
 9 #include <cstdlib>
10 #include <string>
11 #include <set>
12 #include <stack>
13 #define LL long long
14 #define pii pair<int,int>
15 #define INF 0x3f3f3f3f
16 using namespace std;
17 char str[12][100];
18 int n,fail[100],len = 60;
19 void getFail(char *s,int m) {
20     fail[0] = fail[1] = 0;
21     for(int i = 1; i < m; i++) {
22         int j = fail[i];
23         while(j && s[i] != s[j]) j = fail[j];
24         fail[i+1] = str[i] == str[j]?j+1:0;
25     }
26 }
27 bool kmp(char *s,int m,int k) {
28     getFail(s,m);
29     for(int i = 0,j = 0; i < len; i++) {
30         while(j && s[j] != str[k][i]) j = fail[j];
31         if(str[k][i] == s[j]) {
32             j++;
33             if(j == m) return true;
34         }
35     }
36     return false;
37 }
38 int main() {
39     char tmp[100],ans[100];
40     int i,j,k,t;
41     bool flag;
42     scanf("%d",&t);
43     while(t--) {
44         scanf("%d",&n);
45         flag = false;
46         for(i = 0; i < n; i++)
47             scanf("%s",str[i]);
48         len = strlen(str[0]);
49         strcpy(ans,str[0]);
50         for(i = len; i > 2 && !flag; i--) {
51             for(j = 0; j+i <= len; j++) {
52                 strncpy(tmp,str[0]+j,i);
53                 tmp[i] = ‘\0‘;
54                 for(k = 1; k < n; k++)
55                     if(!kmp(tmp,i,k)) break;
56                 if(k == n) {
57                     flag = true;
58                     if(strcmp(ans,tmp) > 0) strcpy(ans,tmp);
59                     else strcpy(ans,tmp);
60                 }
61             }
62         }
63         flag?puts(ans):puts("no significant commonalities");
64     }
65     return 0;
66 }