hdu 4763 kmp ***
找AEAEA形式的字符串最长的A长度，E可以为空
只可意会，不可言传，懂kmp即可
1 #include <stdio.h> 2 #include <string.h> 3 #include <iostream> 4 #include <algorithm> 5 #include <vector> 6 #include <queue> 7 #include <set> 8 #include <map> 9 #include <string> 10 #include <math.h> 11 #include <stdlib.h> 12 #include <time.h> 13 using namespace std; 14 #define cl(a) memset(a,0,sizeof(a)) 15 #define ts printf("*****\n"); 16 void kmp_pre(char x[],int m,int nextt[]) 17 { 18 int i,j; 19 j = nextt[0] = -1; 20 i = 0; 21 while(i < m) 22 { 23 while( -1 != j && x[i] != x[j] )j = nextt[j]; 24 nextt[++i] = ++j; 25 } 26 } 27 char str[1000010]; 28 int nextt[1000010]; 29 bool f[1000010]; 30 int main() 31 { 32 #ifndef ONLINE_JUDGE 33 freopen("1.in","r",stdin); 34 #endif 35 int T; 36 scanf("%d",&T); 37 while(T--) 38 { 39 scanf("%s",str); 40 int n = strlen(str); 41 kmp_pre(str,n,nextt); 42 memset(f,false,sizeof(f)); 43 int tmp = n; 44 while(tmp > 0) 45 { 46 if(n >= 2*tmp) 47 { 48 f[tmp] = true; 49 } 50 tmp = nextt[tmp]; 51 } 52 int ans = 0; 53 for(int i = 2;i <n-1;i++) 54 { 55 tmp = i; 56 while(tmp > 0) 57 { 58 if(f[tmp] && i >= 2*tmp && n >= i+tmp) 59 { 60 ans = max(ans,tmp); 61 break; 62 } 63 tmp = nextt[tmp]; 64 } 65 } 66 printf("%d\n",ans); 67 } 68 return 0; 69 }
