zoukankan      html  css  js  c++  java
  • POJ 2752 Seek the Name, Seek the Fame [kmp]

    Seek the Name, Seek the Fame
    Time Limit: 2000MS   Memory Limit: 65536K
    Total Submissions: 17898   Accepted: 9197

    Description

    The little cat is so famous, that many couples tramp over hill and dale to Byteland, and asked the little cat to give names to their newly-born babies. They seek the name, and at the same time seek the fame. In order to escape from such boring job, the innovative little cat works out an easy but fantastic algorithm: 

    Step1. Connect the father's name and the mother's name, to a new string S. 
    Step2. Find a proper prefix-suffix string of S (which is not only the prefix, but also the suffix of S). 

    Example: Father='ala', Mother='la', we have S = 'ala'+'la' = 'alala'. Potential prefix-suffix strings of S are {'a', 'ala', 'alala'}. Given the string S, could you help the little cat to write a program to calculate the length of possible prefix-suffix strings of S? (He might thank you by giving your baby a name:) 

    Input

    The input contains a number of test cases. Each test case occupies a single line that contains the string S described above. 

    Restrictions: Only lowercase letters may appear in the input. 1 <= Length of S <= 400000. 

    Output

    For each test case, output a single line with integer numbers in increasing order, denoting the possible length of the new baby's name.

    Sample Input

    ababcababababcabab
    aaaaa
    

    Sample Output

    2 4 9 18
    1 2 3 4 5
    

    Source


    题意:给定字符串S,问所有满足既是S的前缀,又是S的后缀的子串的长度

    若将i的父结点设为f[i],那么会形成一棵树。
    对于i的祖先j,一定满足S[1,j]=S[i-j+1,i]。并且满足S[1,j]=S[i-j+1,i]的j,一定是i的祖先。
    本题求的就是S的所有祖先的长度。
    也就是说,它的失配函数的相同前后缀一定也是它的相同前后缀(相同前后缀的相同前后缀)
    注意|S|一定成立
    又犯了数组大小的沙茶错误
    //
    //  main.cpp
    //  poj3461
    //
    //  Created by Candy on 10/19/16.
    //  Copyright ? 2016 Candy. All rights reserved.
    //
    
    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <algorithm>
    using namespace std;
    const int N=4e5+5;
    int f[N],n;
    char s[N];
    void getFail(){
        f[1]=0;
        for(int i=2;i<=n;i++){
            int j=f[i-1];
            while(j&&s[i]!=s[j+1]) j=f[j];
            f[i]=s[i]==s[j+1]?j+1:0;
        }
    }
    int ans[N],m=0;
    void sol(){
        m=0;
        getFail();
        int j=f[n];
        while(j){ans[++m]=j;j=f[j];}
        for(int i=m;i>=1;i--) printf("%d ",ans[i]);
        printf("%d
    ",n);
    }
    int main(){
        //freopen("in.txt","r",stdin);
        while(scanf("%s",s+1)!=EOF){
            n=strlen(s+1);
            sol();
        }
        return 0;
    }
     
     
     
  • 相关阅读:
    onload执行顺序
    让EXCHANGE可以接收外部邮件服务器发送的邮件
    QQ网站里AppTui对象脚本
    owa2007写新邮件时已经选择人员不能带入到与通讯录选人界面问题解决方法
    qq网站里动态加载脚本的实现
    qq网站里对元素的操作方法
    让Exchange可以发送邮件到互联网的邮件服务器
    js实现的hashtable
    无线网卡共享网络发射
    css省略号效果
  • 原文地址:https://www.cnblogs.com/candy99/p/6219056.html
Copyright © 2011-2022 走看看