CodeForces 707B Bakery

枚举。

枚举每一条边,如果发现边的一端$f[u]=1$,另一端$f[v]=0$,那么更新答案,取最小值就好了。

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<iostream>
using namespace std;
typedef long long LL;
const double pi=acos(-1.0),eps=1e-6;
void File()
{
    freopen("D:\\in.txt","r",stdin);
    freopen("D:\\out.txt","w",stdout);
}
template <class T>
inline void read(T &x)
{
    char c = getchar(); x = 0;while(!isdigit(c)) c = getchar();
    while(isdigit(c)) { x = x * 10 + c - '0'; c = getchar();  }
}

const int INF=0x7FFFFFFF;
const int maxn=100010;
int n,m,k;
bool f[maxn];
struct X{int u,v,w;}s[maxn];

int main()
{
    scanf("%d%d%d",&n,&m,&k);
    for(int i=1;i<=m;i++) scanf("%d%d%d",&s[i].u,&s[i].v,&s[i].w);
    for(int i=1;i<=k;i++)
    {
        int x; scanf("%d",&x);
        f[x]=1;
    }
    int ans=INF;
    for(int i=1;i<=m;i++)
    {
        if(f[s[i].u]&&f[s[i].v]) continue;
        if(!f[s[i].u]&&!f[s[i].v]) continue;
        ans=min(ans,s[i].w);
    }
    if(ans==INF) printf("-1\n");
    else printf("%d\n",ans);
    return 0;
}

 

posted @ 2016-09-03 09:55  Fighting_Heart  阅读(340)  评论(5编辑  收藏  举报