HDOJ 题目2594Simpsons’ Hidden Talents(KMP)

Simpsons’ Hidden Talents

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3124    Accepted Submission(s): 1181

Problem Description

Homer: Marge, I just figured out a way to discover some of the talents we weren’t aware we had.
Marge: Yeah, what is it?
Homer: Take me for example. I want to find out if I have a talent in politics, OK?
Marge: OK.
Homer: So I take some politician’s name, say Clinton, and try to find the length of the longest prefix
in Clinton’s name that is a suffix in my name. That’s how close I am to being a politician like Clinton
Marge: Why on earth choose the longest prefix that is a suffix???
Homer: Well, our talents are deeply hidden within ourselves, Marge.
Marge: So how close are you?
Homer: 0!
Marge: I’m not surprised.
Homer: But you know, you must have some real math talent hidden deep in you.
Marge: How come?
Homer: Riemann and Marjorie gives 3!!!
Marge: Who the heck is Riemann?
Homer: Never mind.
Write a program that, when given strings s1 and s2, finds the longest prefix of s1 that is a suffix of s2.

 

Input

Input consists of two lines. The first line contains s1 and the second line contains s2. You may assume all letters are in lowercase.

 

Output

Output consists of a single line that contains the longest string that is a prefix of s1 and a suffix of s2, followed by the length of that prefix. If the longest such string is the empty string, then the output should be 0.
The lengths of s1 and s2 will be at most 50000.

 

Sample Input

clintonhomerriemannmarjorie

 

Sample Output

0rie 3

 

Source

HDU 2010-05 Programming Contest

 

Recommend

lcy   |   We have carefully selected several similar problems for you:  1686 2595 2596 2597 2598 

 

还是感觉不是特别懂，看着别人代码a的

经常看看理解理解吧

#include<stdio.h>#include<string.h>int next[100010];void getnext(char *s){    int len=strlen(s);    int j=0,k=-1;    next[0]=-1;    while(j<len)    {        if(k==-1||s[j]==s[k])        {            j++;            k++;            next[j]=k;        }        else            k=next[k];    }}int kmp(char *a,char *b){    int len1=strlen(a);    int len2=strlen(b);    int i=0,j=0;    getnext(a);    while(i<len2)//不要写i<len2&&j<len1    {        if(j==-1||b[i]==a[j])        {            i++;j++;        }        else            j=next[j];    }    return j;}int main(){    char s1[50005],s2[50005];    while(scanf("%s%s",s1,s2)!=EOF)    {        int len1=strlen(s1);        int len2=strlen(s2),k,i;        //getnext(s1);        k=kmp(s1,s2);        if(k)        {            for(i=0;i<k;i++)            {                printf("%c",s1[i],k);            }            printf(" %d\n",k);        }        else            printf("0\n");    }}