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

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;
#define cl(a) memset(a,0,sizeof(a))
#define ts printf("*****
");
void kmp_pre(char x[],int m,int nextt[])
{
    int i,j;
    j = nextt[0] = -1;
    i = 0;
    while(i < m)
    {
        while( -1 != j && x[i] != x[j] )j = nextt[j];
        nextt[++i] = ++j;
    }
}
char str[1000010];
int nextt[1000010];
bool f[1000010];
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("1.in","r",stdin);
    #endif
    int T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%s",str);
        int n = strlen(str);
        kmp_pre(str,n,nextt);
        memset(f,false,sizeof(f));
        int tmp = n;
        while(tmp > 0)
        {
            if(n >= 2*tmp)
            {
                f[tmp] = true;
            }
            tmp = nextt[tmp];
        }
        int ans = 0;
        for(int i = 2;i <n-1;i++)
        {
            tmp = i;
            while(tmp > 0)
            {
                if(f[tmp] && i >= 2*tmp && n >= i+tmp)
                {
                    ans = max(ans,tmp);
                    break;
                }
                tmp = nextt[tmp];
            }
        }
        printf("%d
",ans);
    }
    return 0;
}