dijkstra algo

  #include <stdio.h>

  #include <stdlib.h>

  #define INFINITY 9999

  int main() {

        int vertexCount, **edgeLength, **res;

        int i, j, k;

        printf("Enter the no of vertices:");

        scanf("%d", &vertexCount);

        edgeLength = (int **)calloc(sizeof(int),  vertexCount);

        res = (int **)calloc(sizeof(int), vertexCount);

        for (i = 0; i < vertexCount; i++) {

                edgeLength[i] = (int *)calloc(sizeof(int),  vertexCount);

                res[i] = (int *)calloc(sizeof(int), vertexCount);

        }

        /* Adjacency Matrix to store Cost of the edges */

        for (i = 0; i < vertexCount; i++) {

                for (j = 0; j < vertexCount; j++) {

                        printf("Edge weight %d to %d(0 if no edge):", i + 1, j + 1);

                        scanf("%d", &edgeLength[i][j]);

                        if (edgeLength[i][j] == 0) {

                                res[i][j] = INFINITY;

                        } else {

                                res[i][j] = edgeLength[i][j];

                        }

                }

        }

        printf("Adjacent matrix for edge weights:\n");

        for (i = 0; i < vertexCount; i++) {

                for (j = 0; j < vertexCount; j++) {

                        printf("%3d", edgeLength[i][j]);

                }

                printf("\n");

        }

        /* Calculate shortest path from each vertex to every other vertices */

        for (i = 0; i < vertexCount; i++) {

                for (j = 0; j < vertexCount; j++) {

                        for (k = 0; k < vertexCount; k++) {

                                if (res[j][k] > res[j][i] + res[i][k]) {

                                        res[j][k] = res[j][i] + res[i][k];

                                }

                        }

                }

        }

        printf("\nShortest path between vertices\n");

        for (i = 0; i < vertexCount; i++) {

                for (j = 0; j < vertexCount; j++) {

                        if (res[i][j] == INFINITY)

                                printf("%3d", 0);

                        else

                                printf("%3d", res[i][j]);

                }

                printf("\n");

        }

        return 0;

  }