Since nCr is same as nC ( n - r ) To decrease number of iterations
if ( r > n / 2 ) : NEW_LINE INDENT r = n - r ; NEW_LINE DEDENT answer = 1 ; NEW_LINE for i in range ( 1 , r + 1 ) : NEW_LINE INDENT answer *= ( n - r + i ) ; NEW_LINE answer /= i ; NEW_LINE DEDENT return answer ; NEW_LINE