Period UVALive - 3026（next数组）

#include <iostream>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <map>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#define rap(i, a, n) for(int i=a; i<=n; i++)
#define rep(i, a, n) for(int i=a; i<n; i++)
#define lap(i, a, n) for(int i=n; i>=a; i--)
#define lep(i, a, n) for(int i=n; i>a; i--)
#define MOD 2018
#define LL long long
#define ULL unsigned long long
#define Pair pair<int, int>
#define mem(a, b) memset(a, b, sizeof(a))
#define _  ios_base::sync_with_stdio(0),cin.tie(0)
//freopen("1.txt", "r", stdin);
using namespace std;
const int maxn = 1000010, INF = 0x7fffffff;
int nex[maxn];
int tlen;
string str;
void get_nex()
{
    mem(nex, 0);
    int j, k;
    j = 0, k = -1, nex[0] = -1;
    while(j < tlen)
    {
        if(k == -1 || str[j] == str[k])
            nex[++j] = ++k;
        else
            k = nex[k];
    }
}

int main()
{
    int n, kase = 0;
    while(cin>> n && n)
    {
        cin>> str;
        tlen = str.size();
        get_nex();
        printf("Test case #%d\n", ++kase);
        for(int i=1; i<=n; i++)
        {
            if(i % (i-nex[i]) == 0 && i /(i - nex[i]) >= 2)
                cout<< i << " " << i/(i - nex[i]) <<endl;
        }
        cout<< endl;
    }

    return 0;
}