Reverse Integer.go

func reverse(x int) int {
	isMinus := false
	var remain = x
	if 0 > x {
		isMinus = true
		remain = -x
	}
	var acc = 0
	for 0 < remain {
		acc = acc * 10 + (remain % 10)
		remain /= 10
	}

	if isMinus {
		if (1 << 31) < acc {
			return 0
		}
		return -acc
	}
	if (1 << 31) - 1 < acc {
		return 0
	}
	return acc
}