2022-02-16：将数组分割成和相等的子数组。 给定一个有 n

package main

import "fmt"

func main() {
    ret := splitArray([]int{1, 2, 1, 2, 1, 2, 1})
    fmt.Println(ret)
}

func splitArray(nums []int) bool {
    if len(nums) < 7 {
        return false
    }
    sumLeftToRight := make([]int, len(nums))
    sumRightToLeft := make([]int, len(nums))
    s := 0
    for i := 0; i < len(nums); i++ {
        sumLeftToRight[i] = s
        s += nums[i]
    }
    s = 0
    for i := len(nums) - 1; i >= 0; i-- {
        sumRightToLeft[i] = s
        s += nums[i]
    }
    for i := 1; i < len(nums)-5; i++ {
        for j := len(nums) - 2; j > i+3; j-- {
            if sumLeftToRight[i] == sumRightToLeft[j] && find(sumLeftToRight, sumRightToLeft, i, j) {
                return true
            }
        }
    }
    return false
}

func find(sumLeftToRight, sumRightToLeft []int, l, r int) bool {
    s := sumLeftToRight[l]
    prefix := sumLeftToRight[l+1]
    suffix := sumRightToLeft[r-1]
    for i := l + 2; i < r-1; i++ {
        s1 := sumLeftToRight[i] - prefix
        s2 := sumRightToLeft[i] - suffix
        if s1 == s2 && s1 == s {
            return true
        }
    }
    return false
}