UVA 11218 KTV

UVA_11218

    这个题目可以直接用回溯解决。

#include<stdio.h>
#include<string.h>
int n,A[10],ans;
int a[100],b[100],c[100],s[100];
void dfs(int cur,int complete,int score)
{
    int i;
    if(complete==3)
    {
        if(score>ans)
            ans=score;
        return;
    }
    for(i=cur;i<n;i++)
        if(!A[a[i]]&&!A[b[i]]&&!A[c[i]])
        {
            A[a[i]]=A[b[i]]=A[c[i]]=1;
            dfs(i+1,complete+1,score+s[i]);
            A[a[i]]=A[b[i]]=A[c[i]]=0;
        }
}
int main()
{
    int i,j,k,t;
    t=0;
    while(1)
    {
        scanf("%d",&n);
        if(n==0)
            break;
        for(i=0;i<n;i++)
            scanf("%d%d%d%d",&a[i],&b[i],&c[i],&s[i]);
        ans=0;
        memset(A,0,sizeof(A));
        dfs(0,0,0);
        printf("Case %d: ",++t);
        if(ans>0)
            printf("%d\n",ans);
        else
            printf("-1\n");
    }
    return 0;    
}