CODEFORCES 25E Test

题意

三个字符串，找一个字符串（它的子串含有以上三个字符串）使它的长度最短，输出此字符串的长度。

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题解

先枚举字符串排列，直接KMP两两匹配，拼接即可。。。答案取最小值。。

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常数巨大的丑陋代码

# include <stdio.h>
# include <stdlib.h>
# include <iostream>
# include <string.h>
# include <algorithm>
using namespace std;

# define IL inline
# define RG register
# define UN unsigned
# define ll long long
# define rep(i, a, b) for(RG int i = a; i <= b; i++)
# define per(i, a, b) for(RG int i = b; i >= a; i--)
# define mem(a, b) memset(a, b, sizeof(a))
# define max(a, b) ((a) > (b)) ? (a) : (b)
# define min(a, b) ((a) < (b)) ? (a) : (b)
# define Swap(a, b) a ^= b, b ^= a, a ^= b;

const int MAXN = 100001;
int len, nt[MAXN], cnt = 2147483647;
char ans[MAXN*3];

IL void KMP(RG char s[]){
    RG int l = strlen(s), j = 0;
    mem(nt, 0);
    rep(i, 1, l - 1){
        while(j && s[i] != s[j]) j = nt[j-1];
        if(s[i] == s[j]) j++;
        nt[i] = j;
    }
    j = 0;
    rep(i, 0, len-1){
        while(j && ans[i] != s[j]) j = nt[j-1];
        if(ans[i] == s[j]) j++;
        if(j == l) return; //少了这个会WA!!!
    }
    while(j < l) ans[len++] = s[j++];
}

IL void Work(RG char s1[], char s2[], char s3[]){
    len = strlen(s3);
    rep(i, 0, len-1) ans[i] = s3[i];
    KMP(s1); KMP(s2);
    cnt = min(cnt, len);
}

int main(){
    char ss1[MAXN], ss2[MAXN], ss3[MAXN];
    scanf(" %s %s %s", ss1, ss2, ss3);
    Work(ss1, ss2, ss3);
    Work(ss1, ss3, ss2);
    Work(ss2, ss1, ss3);
    Work(ss2, ss3, ss1);
    Work(ss3, ss1, ss2);
    Work(ss3, ss2, ss1);
    printf("%d\n", cnt);
    return 0;
}