package main

import (
	"fmt"
	"math"
)

// 152. 乘积最大子数组
func maxProduct(nums []int) int {
	// 因为负数的存在使得有负负得正的情况，所以分别维护两个dp数组
	n, res := len(nums), math.MinInt32
	maxDp, minDp := make([]int, n+1, n+1), make([]int, n+1, n+1)
	maxDp[0], minDp[0] = 1, 1
	for i := 0 ; i < n ; i++ {
		v := nums[i]
		maxDp[i+1] = max(maxDp[i] * v , max(v , minDp[i] * v))
		minDp[i+1] = min(minDp[i] * v , min(v , maxDp[i] * v))
		res = max(res,maxDp[i+1])
	}
	return res
}

func max(a, b int) int {
	if a > b {
		return  a
	}
	return  b
}

func min(a, b int) int {
	if a < b {
		return  a
	}
	return b
}

func main() {
	fmt.Println(maxProduct([]int{-2,0,-1}))
}