nyoj 城市平乱(Dijkstra)

裸

  1 #include<iostream>

  2 #include<cstdio>

  3 #include<cstdlib>

  4 #include<cstring>

  5 #include<string>

  6 #include<queue>

  7 #include<algorithm>

  8 #include<map>

  9 #include<iomanip>

 10 #include<climits>

 11 #include<string.h>

 12 #include<cmath>

 13 #include<stdlib.h>

 14 #include<vector>

 15 #include<stack>

 16 #include<set>

 17 using namespace std;

 18 #define INF 1000000007

 19 #define MAXN 2010

 20 #define Mod 1000007

 21 #define N 100010

 22 #define NN 30

 23 #define sigma_size 3

 24 const int MAX = 1000100;

 25 const int maxn = 6e5 + 10;

 26 using namespace std;

 27 typedef long long LL;

 28 

 29 bool vis[1010];

 30 int G[1010][1010];

 31 int army[1100];

 32 int dist[1010];

 33 int n, m, p, q;

 34 int u, v, w, tmp;

 35 

 36 void Dijkstra(int src)

 37 {

 38     int min, pos;

 39     for (int i = 1; i <= m; ++i)

 40         dist[i] = G[src][i];

 41     dist[src] = 0;

 42     vis[src] = true;

 43     for (int i = 1; i <= m; ++i) {

 44         min = MAX;

 45         for (int j = 1; j <= m; ++j) {

 46             if (dist[j] < min && !vis[j]) {

 47                 min = dist[j];

 48                 pos = j;

 49             }

 50         }

 51         if (min == MAX) return;

 52         vis[pos] = true;

 53         for (int j = 1; j <= m; ++j){

 54             if (!vis[j] && dist[pos] + G[pos][j] < dist[j]) {

 55                 dist[j] = dist[pos] + G[pos][j];

 56             }

 57         }

 58     }

 59 }

 60 

 61 void run()

 62 {

 63     scanf("%d%d%d%d", &n, &m, &p, &q);

 64     memset(army,0,sizeof(army));

 65     memset(vis,0,sizeof(vis));

 66     memset(dist,0,sizeof(dist));

 67     for (int i = 0; i <= m; ++i) {

 68         for (int j = 0; j <= m; ++j) {

 69             G[i][j] = G[j][i] = MAX;

 70         }

 71     }

 72     for (int i = 0; i < n; ++i) {

 73         scanf("%d", &tmp);

 74         army[tmp] = 1;

 75     }

 76     for (int i = 1; i <= p; ++i) {

 77         scanf("%d%d%d", &u, &v, &w);

 78         if (G[u][v] > w) G[u][v] = G[v][u] = w;

 79     }

 80     Dijkstra(q);

 81     /*for (int i = 1; i <= m; ++i)

 82         cout << dist[i] << " ";

 83     cout << endl;*/

 84     int mmax = MAX;

 85     for (int i = 1; i <= m; ++i) {

 86         if (mmax > dist[i] && army[i])

 87             mmax = dist[i];

 88     }

 89     printf("%d\n",mmax);

 90     //system("pause");

 91 }

 92 

 93 int main()

 94 {

 95     int T;

 96     scanf("%d",&T);

 97     while (T--)

 98         run();

 99     return 0;

100 }