2016年天梯赛模拟 5-14 喊山

#include<stack>
#include<queue>
#include<cmath>
#include<vector>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define inf 99999
int n,m,k;
vector<int>G[10002];
queue<int>q;
typedef struct
{
    int id,l;
}d;
d dis[10002];

bool cmp(d a, d b)
{
    return a.l < b.l;
}

int spfa(int x)
{
    while(!q.empty()) q.pop();
    bool inq[10002];
    for(int i=1;i<=n;i++) {dis[i].l = inf;dis[i].id = i;}
    memset(inq,false,sizeof(inq));
    dis[0].l = -1;
    dis[x].l = 0;
    inq[x] = true;
    q.push(x);
    while(!q.empty())
    {
        int u = q.front(); q.pop(); inq[u] = false;
        for(int i=0;i<G[u].size();i++)
        {
            int v = G[u][i];
            if(dis[u].l + 1 < dis[v].l)
            {
                dis[v].l = dis[u].l + 1;
                if(!inq[v]){
                    inq[v] = true;
                    q.push(v);
                }
            }
        }
    }
    sort(dis,dis+n+1,cmp);

    int max1,ans;
    for(int i=n;i>=1;i--)
    {
        if(dis[i].l == inf){
            continue;
        }
        else{
            max1 = dis[i].l;
            ans = i;
            break;
        }
    }

    for(int i=ans - 1;i>=1;i--)
    {
        if(dis[i].l != max1)
        {
            return dis[i+1].id;
        }
    }

}

int main()
{
    int x,y;
    scanf("%d%d%d",&n,&m,&k);
    for(int i=0;i<m;i++)
    {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1;i<=k;i++)
    {
        int qu;
        scanf("%d",&qu);
        if(G[qu].size() == 0)
        {
            printf("0\n");
            continue;
        }
        printf("%d\n",spfa(qu));
    }
}