hihoCoder#1081 最短路径·一

#include <iostream>
#include <vector>
#include <set>
#include <cstring>

using namespace std;

#define MAX_POINT 1024
#define MAX_EDGE 16384

int N, M, S, T;
int graph[MAX_POINT][MAX_POINT];
int v[MAX_POINT];

void bfs() {
v[S] = 1;
while (true) {
int k = 0;
for (int i = 1; i <= N; i++) {
if (!v[i] && graph[S][i] < graph[S][k])
k = i;
}
if (k == T)
break;
v[k] = 1;
for (int i = 1; i <= N; i++)
if (!v[i] && graph[S][i] > graph[S][k] + graph[k][i])
graph[S][i] = graph[S][k] + graph[k][i];
}
}

int main() {
memset(v, 0, sizeof(v));
memset(graph, 64, sizeof(graph));

scanf("%d%d%d%d", &N, &M, &S, &T);
for (int i = 0; i < M; i++) {
int u, v, len;
scanf("%d%d%d", &u, &v, &len);
graph[u][v] = graph[v][u] = min(graph[u][v], len);
}

bfs();

printf("%d\n", graph[S][T]);
}