Dijkstra’s Algorithm code in C
#include<stdio.h>#include<conio.h>#define INFINITY 9999#define MAX 10 void dijikstra(int G[MAX][MAX], int n, int startnode); void main(){ int G[MAX][MAX], i, j, n, u; clrscr(); printf("\nEnter the no. of vertices:: "); scanf("%d", &n); printf("\nEnter the adjacency matrix::\n"); for(i=0;i < n;i++) for(j=0;j < n;j++) scanf("%d", &G[i][j]); printf("\nEnter the starting node:: "); scanf("%d", &u); dijikstra(G,n,u); getch();} void dijikstra(int G[MAX][MAX], int n, int startnode){ int cost[MAX][MAX], distance[MAX], pred[MAX]; int visited[MAX], count, mindistance, nextnode, i,j; for(i=0;i < n;i++) for(j=0;j < n;j++) if(G[i][j]==0) cost[i][j]=INFINITY; else cost[i][j]=G[i][j]; for(i=0;i< n;i++) { distance[i]=cost[startnode][i]; pred[i]=startnode; visited[i]=0; } distance[startnode]=0; visited[startnode]=1; count=1; while(count < n-1){ mindistance=INFINITY; for(i=0;i < n;i++) if(distance[i] < mindistance&&!visited[i]) { mindistance=distance[i]; nextnode=i; } visited[nextnode]=1; for(i=0;i < n;i++) if(!visited[i]) if(mindistance+cost[nextnode][i] < distance[i]) { distance[i]=mindistance+cost[nextnode][i]; pred[i]=nextnode; } count++; } for(i=0;i < n;i++) if(i!=startnode) { printf("\nDistance of %d = %d", i, distance[i]); printf("\nPath = %d", i); j=i; do { j=pred[j]; printf(" <-%d", j); } while(j!=startnode); }} 