# C Program to implement Floyd’s Algorithm

Levels of difficulty: / perform operation:

Floyd’s algorithm uses to find the least-expensive paths between all the vertices in a Graph.

### C Program

#include<stdio.h>
#include<conio.h>
int min(int,int);
void floyds(int p[10][10],int n) {
int i,j,k;
for (k=1;k<=n;k++)
for (i=1;i<=n;i++)
for (j=1;j<=n;j++)
if(i==j)
p[i][j]=0; else
p[i][j]=min(p[i][j],p[i][k]+p[k][j]);
}
int min(int a,int b) {
if(a<b)
return(a); else
return(b);
}
void main() {
int p[10][10],w,n,e,u,v,i,j;
;
clrscr();
printf("\n Enter the number of vertices:");
scanf("%d",&n);
printf("\n Enter the number of edges:\n");
scanf("%d",&e);
for (i=1;i<=n;i++) {
for (j=1;j<=n;j++)
p[i][j]=999;
}
for (i=1;i<=e;i++) {
printf("\n Enter the end vertices of edge%d with its weight \n",i);
scanf("%d%d%d",&u,&v,&w);
p[u][v]=w;
}
printf("\n Matrix of input data:\n");
for (i=1;i<=n;i++) {
for (j=1;j<=n;j++)
printf("%d \t",p[i][j]);
printf("\n");
}
floyds(p,n);
printf("\n Transitive closure:\n");
for (i=1;i<=n;i++) {
for (j=1;j<=n;j++)
printf("%d \t",p[i][j]);
printf("\n");
}
printf("\n The shortest paths are:\n");
for (i=1;i<=n;i++)
for (j=1;j<=n;j++) {
if(i!=j)
printf("\n <%d,%d>=%d",i,j,p[i][j]);
}
getch();
}