Cyclic Nacklace

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K
(Java/Others)
Total Submission(s): 3253 Accepted Submission(s): 1488

Problem Description

CC always becomes very depressed at the end of this month, he has checked his
credit card yesterday, without any surprise, there are only 99.9 yuan left. he
is too distressed and thinking about how to tide over the last days. Being
inspired by the entrepreneurial spirit of “HDU CakeMan”, he wants to sell some
little things to make money. Of course, this is not an easy task.

As Christmas is around the corner, Boys are busy in choosing christmas
presents to send to their girlfriends. It is believed that chain bracelet is a
good choice. However, Things are not always so simple, as is known to
everyone, girl’s fond of the colorful decoration to make bracelet appears
vivid and lively, meanwhile they want to display their mature side as college
students. after CC understands the girls demands, he intends to sell the chain
bracelet called CharmBracelet. The CharmBracelet is made up with colorful
pearls to show girls’ lively, and the most important thing is that it must be
connected by a cyclic chain which means the color of pearls are cyclic
connected from the left to right. And the cyclic count must be more than one.
If you connect the leftmost pearl and the rightmost pearl of such chain, you
can make a CharmBracelet. Just like the pictrue below, this CharmBracelet’s
cycle is 9 and its cyclic count is 2:

Now CC has brought in some ordinary bracelet chains, he wants to buy minimum
number of pearls to make CharmBracelets so that he can save more money. but
when remaking the bracelet, he can only add color pearls to the left end and
right end of the chain, that is to say, adding to the middle is forbidden.
CC is satisfied with his ideas and ask you for help.

Input

The first line of the input is a single integer T ( 0 < T <= 100 ) which
means the number of test cases.
Each test case contains only one line describe the original ordinary chain to
be remade. Each character in the string stands for one pearl and there are 26
kinds of pearls being described by ‘a’ ~’z’ characters. The length of the
string Len: ( 3 <= Len <= 100000 ).

Output

For each case, you are required to output the minimum count of pearls added to
make a CharmBracelet.

Sample Input

3 aaa abca abcde

Sample Output

0 2 5

Author

possessor WC

Source

HDU 3rd “Vegetable-Birds Cup” Programming Open Contest

求循环节 http://www.cnblogs.com/wuyiqi/archive/2012/01/06/2314078.html

#include<stdio.h>
#include<iostream>
#include<math.h>
#include<stdlib.h>
#include<ctype.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<queue>
#include<stack>
#include<set>
#include<map>

using namespace std;

char  b[100050];
int Next[100050];

void get_next(char b[], int m)
{
    int i = 0;
    Next[0] = -1;
    int j = -1;
    while (i<m)
    {
        if (j == -1 || b[i] == b[j])
        {
            ++i;
            ++j;
            if (b[i] == b[j])
                Next[i] = Next[j];
            else
                Next[i] = j;
        }
        else
            j = Next[j];
    }
}

int main()
{
    int test, n, m, i, j;
    scanf("%d", &test);
    while (test--)
    {
        scanf("%s",b);
        int m = strlen(b);
        get_next(b, m);
        int t = Next[m];
        if (t == 0)
        {
            printf("%d\n",m);
            continue;
        }
        int s = m - t;
        if (m%s == 0)
            printf("0\n");
        else
            printf("%d\n",s-m%s);
    }
}