[kuangbin带你飞]专题十六 KMP & 扩展KMP & Manacher F - The Minimum Length HUST - 1010 （kmp循环节）...

╰+攻爆jí腚メ 2023-08-17 15:41 105阅读 0赞

# F - The Minimum Length HUST - 1010  #

题目链接：[https://vjudge.net/contest/70325\#problem/F][https_vjudge.net_contest_70325_problem_F]

题目：

There is a string A. The length of A is less than 1,000,000. I rewrite it again and again. Then I got a new string: AAAAAA...... Now I cut it from two different position and get a new string B. Then, give you the string B, can you tell me the length of the shortest possible string A.  
For example, A="abcdefg". I got abcd **efgabcdefgabcde**fgabcdefg.... Then I cut the red part: efgabcdefgabcde as string B. From B, you should find out the shortest A.  
  
InputMultiply Test Cases.  
For each line there is a string B which contains only lowercase and uppercase charactors.  
The length of B is no more than 1,000,000.  
OutputFor each line, output an integer, as described above.Sample Input

bcabcab
    efgabcdefgabcde

Sample Output

3
    7
    题意：求最小循环节的长度
    思路：kmp中n-next[n]就是最小循环节的长度，由于现在该题不支持提交，我就贴一下我写的

// 
    // Created by HJYL on 2019/8/15.
    //
    
    #include <iostream>
    #include <vector>
    #include <map>
    #include <string>
    #include <queue>
    #include <stack>
    #include <set>
    #include <algorithm>
    #include <cstdio>
    #include <cstring>
    #include <cmath>
    #include <cstdlib>
    using namespace std;
    const int maxn=1e6+10;
    char str[maxn];
    int nextt[maxn];
    void getnext()
    {
        int i=0,j=-1;
        nextt[0]=-1;
        int n=strlen(str);
        while(i<n)
        {
            if(j==-1||str[i]==str[j])
            {
                i++,j++;
                if(str[i]!=str[j])
                    nextt[i]=j;
                else
                    nextt[i]=nextt[j];
            } else
                j=nextt[j];
        }
    }
    int main()
    {
        //freopen("C:\\Users\\asus567767\\CLionProjects\\untitled\\text","r",stdin);
        while(~scanf("%s",str))
        {
            getnext();
            int len=strlen(str);
            printf("%d\n",len-nextt[len]);
        }
        return 0;
    }

转载于:https://www.cnblogs.com/Vampire6/p/11360768.html

[https_vjudge.net_contest_70325_problem_F]: https://vjudge.net/contest/70325#problem/F