Dijkstra’s algo

// A C++ program for Dijkstra's single source shortest path algorithm. 
// The program is for adjacency matrix representation of the graph 

#include <limits.h> 
#include <stdio.h> 

// Number of vertices in the graph 
#define V 9 

// A utility function to find the vertex with minimum distance value, from 
// the set of vertices not yet included in shortest path tree 
int minDistance(int dist[], bool sptSet[]) 
{ 
	// Initialize min value 
	int min = INT_MAX, min_index; 

	for (int v = 0; v < V; v++) 
		if (sptSet[v] == false && dist[v] <= min) 
			min = dist[v], min_index = v; 

	return min_index; 
} 

// A utility function to print the constructed distance array 
void printSolution(int dist[]) 
{ 
	printf("Vertex \t\t Distance from Source\n"); 
	for (int i = 0; i < V; i++) 
		printf("%d \t\t %d\n", i, dist[i]); 
} 

// Function that implements Dijkstra's single source shortest path algorithm 
// for a graph represented using adjacency matrix representation 
void dijkstra(int graph[V][V], int src) 
{ 
	int dist[V]; // The output array. dist[i] will hold the shortest 
	// distance from src to i 

	bool sptSet[V]; // sptSet[i] will be true if vertex i is included in shortest 
	// path tree or shortest distance from src to i is finalized 

	// Initialize all distances as INFINITE and stpSet[] as false 
	for (int i = 0; i < V; i++) 
		dist[i] = INT_MAX, sptSet[i] = false; 

	// Distance of source vertex from itself is always 0 
	dist[src] = 0; 

	// Find shortest path for all vertices 
	for (int count = 0; count < V - 1; count++) { 
		// Pick the minimum distance vertex from the set of vertices not 
		// yet processed. u is always equal to src in the first iteration. 
		int u = minDistance(dist, sptSet); 

		// Mark the picked vertex as processed 
		sptSet[u] = true; 

		// Update dist value of the adjacent vertices of the picked vertex. 
		for (int v = 0; v < V; v++) 

			// Update dist[v] only if is not in sptSet, there is an edge from 
			// u to v, and total weight of path from src to v through u is 
			// smaller than current value of dist[v] 
			if (!sptSet[v] && graph[u][v] && dist[u] != INT_MAX 
				&& dist[u] + graph[u][v] < dist[v]) 
				dist[v] = dist[u] + graph[u][v]; 
	} 

	// print the constructed distance array 
	printSolution(dist); 
} 

// driver program to test above function 
int main() 
{ 
	/* Let us create the example graph discussed above */
	int graph[V][V] = { { 0, 4, 0, 0, 0, 0, 0, 8, 0 }, 
						{ 4, 0, 8, 0, 0, 0, 0, 11, 0 }, 
						{ 0, 8, 0, 7, 0, 4, 0, 0, 2 }, 
						{ 0, 0, 7, 0, 9, 14, 0, 0, 0 }, 
						{ 0, 0, 0, 9, 0, 10, 0, 0, 0 }, 
						{ 0, 0, 4, 14, 10, 0, 2, 0, 0 }, 
						{ 0, 0, 0, 0, 0, 2, 0, 1, 6 }, 
						{ 8, 11, 0, 0, 0, 0, 1, 0, 7 }, 
						{ 0, 0, 2, 0, 0, 0, 6, 7, 0 } }; 

	dijkstra(graph, 0); 

	return 0; 
}