Create BellmanFord.cpp

Dynamic Programming/BellmanFord.cpp

@@ -0,0 +1,117 @@
+#include <bits/stdc++.h> 
+
+struct Edge { 
+	int src, dest, weight; 
+}; 
+
+struct Graph { 
+
+	int V, E; 
+
+
+	struct Edge* edge; 
+}; 
+
+
+struct Graph* createGraph(int V, int E) 
+{ 
+	struct Graph* graph = new Graph; 
+	graph->V = V; 
+	graph->E = E; 
+	graph->edge = new Edge[E]; 
+	return graph; 
+} 
+
+
+void printArr(int dist[], int n) 
+{ 
+	printf("Vertex Distance from Source\n"); 
+	for (int i = 0; i < n; ++i) 
+		printf("%d \t\t %d\n", i, dist[i]); 
+} 
+
+void BellmanFord(struct Graph* graph, int src) 
+{ 
+	int V = graph->V; 
+	int E = graph->E; 
+	int dist[V]; 
+
+
+	for (int i = 0; i < V; i++) 
+		dist[i] = INT_MAX; 
+	dist[src] = 0; 
+
+
+	for (int i = 1; i <= V - 1; i++) { 
+		for (int j = 0; j < E; j++) { 
+			int u = graph->edge[j].src; 
+			int v = graph->edge[j].dest; 
+			int weight = graph->edge[j].weight; 
+			if (dist[u] != INT_MAX && dist[u] + weight < dist[v]) 
+				dist[v] = dist[u] + weight; 
+		} 
+	} 
+
+
+	for (int i = 0; i < E; i++) { 
+		int u = graph->edge[i].src; 
+		int v = graph->edge[i].dest; 
+		int weight = graph->edge[i].weight; 
+		if (dist[u] != INT_MAX && dist[u] + weight < dist[v]) { 
+			printf("Graph contains negative weight cycle"); 
+			return;  
+		} 
+	} 
+
+	printArr(dist, V); 
+
+	return; 
+} 
+
+int main() 
+{ 
+
+	int V = 5;  
+	int E = 8; 
+	struct Graph* graph = createGraph(V, E); 
+
+
+	graph->edge[0].src = 0; 
+	graph->edge[0].dest = 1; 
+	graph->edge[0].weight = -1; 
+
+
+	graph->edge[1].src = 0; 
+	graph->edge[1].dest = 2; 
+	graph->edge[1].weight = 4; 
+
+
+	graph->edge[2].src = 1; 
+	graph->edge[2].dest = 2; 
+	graph->edge[2].weight = 3; 
+
+	graph->edge[3].src = 1; 
+	graph->edge[3].dest = 3; 
+	graph->edge[3].weight = 2; 
+
+
+	graph->edge[4].src = 1; 
+	graph->edge[4].dest = 4; 
+	graph->edge[4].weight = 2; 
+
+	graph->edge[5].src = 3; 
+	graph->edge[5].dest = 2; 
+	graph->edge[5].weight = 5; 
+
+	graph->edge[6].src = 3; 
+	graph->edge[6].dest = 1; 
+	graph->edge[6].weight = 1; 
+
+	graph->edge[7].src = 4; 
+	graph->edge[7].dest = 3; 
+	graph->edge[7].weight = -3; 
+
+	BellmanFord(graph, 0); 
+
+	return 0; 
+}