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  1. // A C++ program for Dijkstra's single source shortest path algorithm.
  2. // The program is for adjacency matrix representation of the graph
  3.  
  4. #include <stdio.h>
  5. #include <limits.h>
  6. #include <stdbool.h>
  7.  
  8. // Number of vertices in the graph
  9. #define V 4
  10.  
  11. // A utility function to find the vertex with minimum distance value, from
  12. // the set of vertices not yet included in shortest path tree
  13. int minDistance(int dist[], bool sptSet[])
  14. {
  15. // Initialize min value
  16. int min = INT_MAX, min_index;
  17.  
  18. for (int v = 0; v < V; v++)
  19. 	if (sptSet[v] == false && dist[v] <= min)
  20. 		min = dist[v], min_index = v;
  21.  
  22. return min_index;
  23. }
  24.  
  25. // A utility function to print the constructed distance array
  26. int printSolution(int dist[], int n)
  27. {
  28. printf("Vertex Distance from Source\n");
  29. for (int i = 0; i < V; i++)
  30. 	printf("%d tt %d\n", i, dist[i]);
  31. }
  32.  
  33. // Funtion that implements Dijkstra's single source shortest path algorithm
  34. // for a graph represented using adjacency matrix representation
  35. void dijkstra(int graph[V][V], int src)
  36. {
  37. 	int dist[V];	 // The output array. dist[i] will hold the shortest
  38. 					// distance from src to i
  39.  
  40. 	bool sptSet[V]; // sptSet[i] will true if vertex i is included in shortest
  41. 					// path tree or shortest distance from src to i is finalized
  42.  
  43. 	// Initialize all distances as INFINITE and stpSet[] as false
  44. 	for (int i = 0; i < V; i++)
  45. 		dist[i] = INT_MAX, sptSet[i] = false;
  46.  
  47. 	// Distance of source vertex from itself is always 0
  48. 	dist[src] = 0;
  49.  
  50. 	// Find shortest path for all vertices
  51. 	for (int count = 0; count < V; count++)
  52. 	{
  53. 	// Pick the minimum distance vertex from the set of vertices not
  54. 	// yet processed. u is always equal to src in first iteration.
  55. 	int u = minDistance(dist, sptSet);
  56.     printf("\n current Node: %d",u);
  57. 	// Mark the picked vertex as processed
  58. 	sptSet[u] = true;
  59.  
  60. 	// Update dist value of the adjacent vertices of the picked vertex.
  61. 	for (int v = 0; v < V; v++)
  62.  
  63. 		// Update dist[v] only if is not in sptSet, there is an edge from
  64. 		// u to v, and total weight of path from src to v through u is
  65. 		// smaller than current value of dist[v]
  66. 		if (!sptSet[v] && graph[u][v] && dist[u] != INT_MAX
  67. 									&& dist[u]+graph[u][v] < dist[v])
  68. 		{
  69. 			dist[v] = dist[u] + graph[u][v];
  70. 		}
  71. 	}
  72.  
  73. 	// print the constructed distance array
  74. 	printSolution(dist, V);
  75. }
  76.  
  77. // driver program to test above function
  78. int main()
  79. {
  80. /* Let us create the example graph discussed above */
  81. int graph[V][V] = {{0, 4, 1, 0},
  82. 					{0, 0, 0, -3},
  83. 					{0, 0, 0, 2},
  84. 					{0, 0, 0, 0}};
  85.  
  86. 	dijkstra(graph, 0);
  87.  
  88. 	return 0;
  89. }
  90.  
Success #stdin #stdout 0s 4384KB
comments (?)
stdin
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Standard input is empty
stdout
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 current Node: 0
 current Node: 2
 current Node: 3
 current Node: 1Vertex Distance from Source
0 tt 0
1 tt 4
2 tt 1
3 tt 3
https://ideone.com/DtZ3Zt
language:
C (gcc 8.3)
created:
6 years ago
visibility:
public

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