最短路

int dijkstra(int s, int e) {
	priority_queue<P, vector<P>, greater<P>> q;
	memset(d, 0x3f, sizeof(d));
	d[s] = 0;
	q.push(P(0, s));
	while (!q.empty()) {
		P p = q.top();
		q.pop();
		if (p.second == e) return d[e];
		if (d[p.second]< p.first) continue;
		int v = p.second;
		for (int i = 1; i<= n; i++) {
			if (d[i]>d[v] + G[v][i]) {
			d[i] = d[v] + G[v][i];
			q.push(P(d[i], i));
			}
		}
	}
return d[e];
}