kmpnext数组理解循环节 HDU3746

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int n;
int next1[100010];
char s[100010];

void getnext()
{
    int i=0;
    int j=-1;
    next1[0]=-1;
    while(i<n)
    {
        while(j!=-1&&s[i]!=s[j])
        {
            j=next1[j];
        }
        next1[++i]=++j;
    }
}

int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%s",&s);
        n=strlen(s);
        getnext();
        int jie=n-next1[n];
        int ans=jie-next1[n];
        //if(ans<0)
        //    ans=0;
        if(ans!=jie)
            cout<<(ans%jie+jie)%jie<<endl;
        else
            cout<<ans<<endl;
    }
    return 0;
}