牛客网暑期ACM多校训练营(第三场).E. Sort String(KMP)

链接:https://www.nowcoder.com/acm/contest/141/E
来源:牛客网
 

时间限制:C/C++ 1秒,其他语言2秒
空间限制:C/C++ 262144K,其他语言524288K
Special Judge, 64bit IO Format: %lld

题目描述

Eddy likes to play with string which is a sequence of characters. One day, Eddy has played with a string S for a long time and wonders how could make it more enjoyable. Eddy comes up with following procedure:

1. For each i in [0,|S|-1], let Si be the substring of S starting from i-th character to the end followed by the substring of first i characters of S. Index of string starts from 0.
2. Group up all the Si. Si and Sj will be the same group if and only if Si=Sj.
3. For each group, let Lj be the list of index i in non-decreasing order of Si in this group.
4. Sort all the Lj by lexicographical order.

Eddy can't find any efficient way to compute the final result. As one of his best friend, you come to help him compute the answer!

输入描述:

Input contains only one line consisting of a string S.

1≤ |S|≤ 106
S only contains lowercase English letters(i.e. ).

输出描述:

First, output one line containing an integer K indicating the number of lists.
For each following K lines, output each list in lexicographical order.
For each list, output its length followed by the indexes in it separated by a single space.

示例1

输入

复制

abab

输出

复制

2
2 0 2
2 1 3

示例2

输入

复制

deadbeef

输出

复制

8
1 0
1 1
1 2
1 3
1 4
1 5
1 6
1 7

考点:字符串匹配

题意:

根据原字符串构造新串,对于原字符串从0~|S|-1,i从0开始,从i到最后的子串放到从0到i-1子串的前面。对于这些新构造的子串,从0开始编号,将相同的新字符串们归为一组,输出一共有多少组,每组有多少个新字符串,以及新字符串的编号。

 思路:

 只有字符串存在循环子串情况下,才会出现相同的字符串,才会出现多个字符串同组情况。求出循环子串的长度,根据循环子串判断并输出分组情况。

#include <bits/stdc++.h>
const int maxn=1e6+10,mo=1e9+7;
char s[maxn];int f[maxn],n,g;
int main()
{
    scanf("%s",s+1);n=strlen(s+1);
    f[0]=-1;
    for (int i=1,j=-1;i<=n;f[i++]=++j) while (j>=0 && s[j+1]!=s[i]) j=f[j];
    g=(n%(n-f[n])==0)?n-f[n]:n;
    printf("%d\n",g);
    for (int i=0;i<g;i++)
    {
        printf("%d ",n/g);
        for (int j=i;j<n;j+=g)printf("%d ",j);
        puts("");
    }
}

猜你喜欢

转载自blog.csdn.net/XxxxxM1/article/details/81231839
今日推荐