有权图单源最短路径 - Dijkstra算法

如题,下面是C++实现。

int findMinDist(vector<vector<int>>& G, vector<int>& dist, vector<bool>& collected) {
        int minV, minDist = INF;
	    for (int i = 0; i<int(G.size()); ++i) {
	    if (collected[i] == false && dist[i] < minDist) {
			minDist = dist[i];
			minV = i;
		}
	}

	if (minDist < INF)
		return minV;
	else
		return -1;
}

bool dijkstra(vector<vector<int>>& G, int S, vector<int>& dist, vector<int>& path) {
	vector<bool> collected(G.size(), false);
	for (int i = 0; i<int(G.size()); ++i) {
		dist[i] = G[S][i];
		if (G[S][i] < INF) {
			path[i] = S;
		}
	}

	dist[S] = 0;
	collected[S] = true;
	int V = S;
	while (true) {
		V = findMinDist(G, dist, collected);
		if (V == -1)
			break;

		collected[V] = true;
		for (int W = 0; W<int(G[V].size()); ++W) {
			if (collected[W] == false && G[V][W] < INF) {
				if (dist[V] + G[V][W] < dist[W]) {
					dist[W] = dist[V] + G[V][W];
					path[W] = V;
				}
			}
		}
	}

	return true;
}
这是LeetCode的一个简单应用,https://leetcode.com/problems/network-delay-time/。

猜你喜欢

转载自blog.csdn.net/EasonDongH/article/details/85004649
今日推荐