r[0] = Min( a, Min( b, c ) ) r[2] = Max( a, Max( b, c ) ) r[1] = a + b + c - r[0] - r[2] I don't think that can suffer from integer overflow. But it might

r[0] = Min( a, Min( b, c ) ) r[2] = Max( a, Max( b, c ) ) r[1] = a + b + c - r[0] - r[2] I don't think that can suffer from integer overflow. But it might suffer from floating-point rounding problems. Of course you could always go with the boring solution: if a > b: swap( a, b ) if b > c: swap( b, c ) if a > b: swap( a, b )