hdu 1867 A + B for you again KMP

题意：找到两个字符串最长前缀后缀匹配。比并且是输出字符串较小的。

#include <iostream>#include <cstdio>#include<limits>#include <map>#include <cstring>#include <string>#include <cstdlib>using namespace std;const int MAXN=100005;char s1[MAXN], s2[MAXN];int next1[MAXN];int next2[MAXN];void getnext(char s[], int next[]){    int i=0, j=-1;    next[0]=-1;    int len = strlen(s);    while(i<len)    {        if(j==-1||s[i]==s[j])            next[++i]=++j;        else            j=next[j];    }    return ;}int KMP(char s3[], char s4[], int next[]){    int i=0, j=0;    int lena=strlen(s3), lenb=strlen(s4);    while(i<lena&&j<lenb)    {        if(s3[i]==s4[j]||j==-1)            i++, j++;        else            j=next[j];    }    if(i==lena)        return j;    return 0;}int main(){    while(~scanf("%s %s", s1, s2))    {        getnext(s1, next2);        getnext(s2, next1);        int x=KMP(s1, s2, next1);        int y=KMP(s2, s1, next2);        if(x>y)            printf("%s%s\n", s1,s2+x);        else if(x==y)        {            if(strcmp(s1, s2)>0)               printf("%s%s\n", s2, s1+x);            else                printf("%s%s\n", s1, s2+x);        }        else            printf("%s%s\n", s2,s1+y);    }    return 0;}