Simple
c programs

1)

**Factorial**
long Fact ( int n )

{

if ( n>0 )

return( n * Fact (n-1) ); //recursion

else

return( 1 );

}

2)

**GCD**
int GCD( int x, int y ) {

if ( x>=y AND x%y==0 )

return( y );

else if ( x

return( GCD( y, x ) );

else

return( GCD( y, x%y ) );

}