#include <stdio.h>
int a[10][10],visited[10],n,cost=0;
void mincost(int city)
{
int i,ncity; //ncity==nearest city
visited[city]=1;
printf("%d->",city+1);
ncity=least(city);
if(ncity==999) //no nearest city,hence back to 1
{
ncity=0;
printf("%d",ncity+1);
cost+=a[city][ncity];
return;
}
mincost(ncity); //recursive
}
int least(int c)
{
int i,nc=999;
int min=999,kmin;
for(i=0;i<n;i++)
{
if((a[c][i]!=0) && visited[i]==0)
{
if(a[c][i]<min)
{
min=a[i][0]+a[c][i];
kmin=a[c][i];
nc=i;
}
}
}
if(min!=999)
cost+=kmin;
return nc;
}
int main()
{
int n,i,j;
printf("Enter the number of cities:");
scanf("%d",&n);
printf("\nEnter the cost matrix:");
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
scanf("%d",&a[i][j]);
}
}
for(i=0;i<n;i++)
visited[i]=0;
printf("\nThe minimum path is:\n");
mincost(0);
printf("\nMinimum cost:%d",cost);
getch();
return 0;
}
The program finds the cycle with least cost for a given graph. The function least finds the next nearest city denoted by nc & each city is considered one by one by recursively calling mincost function. The output is always the the first city & it's cost,that's it. Please help!
You have a global variable n which gets initialized to zero by the compiler. Then in the main function you have a local variable n that shadows the global variable, so when you read input from the user and initialize n to that, it's only the local variable which is initialized ad not the global which will still be zero.
General tip: Avoid global variables. If you need other functions to know about a value or variable, then pass it as an argument.