238-Product-Of-Array-Except-Self.go

func productExceptSelf(nums []int) []int {
	res := make([]int, len(nums))
	for i := 0; i < len(res); i++ {
		res[i] = 1
	}

	prefix := 1
	for i := 0; i < len(nums); i++ {
		res[i] = prefix
		prefix *= nums[i]
	}

	postfix := 1
	for i := len(nums) - 1; i >= 0; i-- {
		res[i] *= postfix
		postfix *= nums[i]
	}

	return res
}