initialize repository of algorithm-template

dijkstra/dijkstra.cpp

@@ -0,0 +1,35 @@
+class Solution {
+public:
+	int diskstra(vector<vector<int>>& edges, int n, int start, int end) {
+		vector<vector<int>> graph(n, vector<int>(n, INT_MAX / 2));
+		for (auto& edge : edges) {
+			int from = edge[0], to = edge[1], dist = edge[2];
+			graph[from][to] = dist;		// build the graph
+		}
+
+		vector<int> distance(n, INT_MAX / 2), visited(n, 0);
+		distance[start] = 0;
+		while (true) {
+			int next_node = -1;
+			for (int node = 0; node < n; node++) {
+				if (visited[node]) {
+					continue;   // update non-repeatedly
+				}
+				if (next_node < 0 || distance[next_node] > distance[node]) {
+					next_node = node;   // find the node with the smallest moving path
+				}
+			}
+
+			if (next_node < 0 || distance[next_node] == INT_MAX / 2) {
+				break;      // cannot find the node
+			}
+
+			visited[next_node] = 1;
+			for (int node = 0; node < n; node++) {
+				// update the moving paths of the remaining nodes based on the nearest node
+				distance[node] = min(distance[node], distance[next_node] + graph[next_node][node]);
+			}
+		}
+		return distance[end] == INT_MAX / 2 ? -1 : distance[end];
+	}
+};