~cpp 

#include <stdio.h> 
 
int factorial(int n);
int permutation(int n, int r);
int combination(int n,int r);

int main(int argc, char* argv[])
{
	int col,row;
	printf("행 : "); scanf("%d",&row);
	printf("열 : "); scanf("%d",&col);
	printf("result = %d\n",combination(row-1,col-1));

	return 0;
}

int factorial(int n)
{
	if(n==1 || n==0) return 1;
	return n*factorial(n-1);
}

int permutation(int n, int r)
{
	return factorial(n)/factorial(n-r);	
}

int combination(int n,int r)
{
	if(r==0) return 1;
	return permutation(n,r)/factorial(r);
}