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

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

// Number of vertices in the graph
#define V 4

// 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
int printSolution(int dist[], int n)
{
printf("Vertex Distance from Source\n");
for (int i = 0; i < V; i++)
	printf("%d tt %d\n", i, dist[i]);
}

// Funtion 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 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; count++)
	{
	// Pick the minimum distance vertex from the set of vertices not
	// yet processed. u is always equal to src in first iteration.
	int u = minDistance(dist, sptSet);
    printf("\n current Node: %d",u);
	// 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, V);
}

// driver program to test above function
int main()
{
/* Let us create the example graph discussed above */
int graph[V][V] = {{0, 4, 1, 0},
					{0, 0, 0, -3},
					{0, 0, 0, 2},
					{0, 0, 0, 0}};

	dijkstra(graph, 0);

	return 0;
}