Respected members,

I am new student of programming and currently learning C. I have an assignment of generating all possible combinations of n elements out of K numbers. After searching lot on google, I got following code using nested for loop. But its not working for me. Please help me.

Code:

int a = 0;
int b = 0;
int c = 0;
int d = 0;
int k[10]={1,2,3,4,5,6,7,8,9,10};
int n = 4;
int main()
{
for (a = 0; a <= n - 3; ++a)
{
for (b = a+1; b <= n-2; b++)
{
for (c = b+1; c <= n-1; c++)
{
for (d = c+1; d <= n; d++)
{
printf("%d,%d,%d,%d", k[a],k[b],k[c],k[d];
}
}
}
}
}