紫书搜索 例题7-6 UVA

题目链接:

https://vjudge.net/problem/UVA-140

题意:

题解:

代码:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MS(a) memset(a,0,sizeof(a))
#define MP make_pair
#define PB push_back
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3fLL;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
//////////////////////////////////////////////////////////////////////////
const int maxn = 1e5+10;

char s[500];
int mp[30][30],vis[30],save[100],node[100];

int main(){
    while(gets(s)){
        if(!strcmp(s,"#")) break;
        int ans = 10;
        int len = strlen(s);
        MS(vis); MS(mp);
        int u, flag = 0;
        for(int i=0; i<len; i++){
            if(s[i]>='A' && s[i]<='Z')
                vis[s[i]-'A'] = 1;
            if(s[i] == ':'){
                u = s[i-1]-'A';
                flag = 1;
            }else if(flag && s[i]!=';'){
                mp[u][s[i]-'A'] = mp[s[i]-'A'][u] = 1;
            }else{
                flag = 0;
            }
        }
        int cnt = 0;
        for(int i=0; i<26; i++)
            if(vis[i])
                node[cnt++] = i;

        do{
            int num = 0;
            for(int i=0; i<cnt; i++){
                for(int j=i+1; j<cnt; j++){
                    if(mp[node[i]][node[j]])
                        if(j-i > num)
                            num = j-i;
                }
                if(num >= ans) break;
            }
            if(ans > num){
                ans = num;
                memcpy(save,node,sizeof(node));
            }
        }while(next_permutation(node,node+cnt));

        for(int i=0; i<cnt; i++){
            printf("%c ",save[i]+'A');
        }
        printf("-> %d
",ans);

    }

    return 0;
}