HDU3374 字符串最大最小表示法模板

一开始没太看懂什么意思，拿笔反复推了一遍才大概知道最大最小表示法是怎么求的，感觉太神奇了...

#include <iostream>
#include <cstdio>
#include <string.h>
#pragma warning ( disable : 4996 )
using namespace std;

inline int Max(int a,int b) { return a>b?a:b; }
inline int Min(int a,int b) { return a>b?b:a; }
const int inf = 0x3f3f3f3f;
const int maxn = 1e6+5;

char str[maxn];
int nxt[maxn];
int len, plen, minpos, maxpos;

void getNext()
{
    memset( nxt, 0, sizeof(nxt) );
    len = strlen(str);

    int k = -1, j = 0;
    nxt[j] = -1;
    
    while ( j < len )
    {
        if ( k==-1 || str[j]==str[k] )
        {
            k++; j++;
            nxt[j] = k;
        }
        else
            k = nxt[k];
    }
    plen = nxt[len];
}

void getMin()
{
    int tmp, i = 0, j = 1, k = 0;
    while ( i<len && j <len && k <len )
    {
        tmp = str[(i+k)%len]-str[(j+k)%len];
        if(!tmp) k++;
        else
        {
            if(tmp>0) i += k+1;
            else j += k+1;
            if( i == j ) j++;
            k = 0;
        }
    }
    minpos = i<j?i+1:j+1;
}

void getMax()
{
    int tmp, i = 0, j = 1, k = 0;
    while ( i<len && j<len && k<len )
    {
        tmp = str[(i+k)%len]-str[(j+k)%len];
        if(!tmp) k++;
        else
        {
            if(tmp<0) i += k+1;
            else j += k+1;
            if( i == j ) j++;
            k = 0;
        }
    }
    maxpos = i<j?i+1:j+1;
}

int main()
{
    while ( ~scanf("%s", str) )
    {
        getNext();
        getMin();
        getMax();

        int tmp = (len%(len-plen)==0)?(len/(len-plen)):1;
        printf( "%d %d %d %d
", minpos, tmp, maxpos, tmp );
    }
    return 0;
}