Program to print all combinations of numbers 1,2,3.

#include <stdio.h>
main()
{

int iter1=0,iter2=0,iter3=0;
for(iter1=1; iter1<=3; iter1++)
{
for(iter2=1; iter2<=3; iter2++)
{
for(iter3=1; iter3<=3; iter3++)
{
if(iter1 != iter2 && iter2 != iter3 && iter1 != iter3)
{
printf("%d %d %d \n",iter1, iter2, iter3);
}
}
}
}

return 0;
}

OUTPUT:

1 2 3 

1 3 2

2 1 3

2 3 1

3 1 2

3 2 1