1013. Partition Array Into Three Parts With Equal Sum

Given an array A of integers, return true if and only if we can partition the array into three non-empty parts with equal sums.

Formally, we can partition the array if we can find indexes i+1 < j with `(A[0] + A[1] + ... + A[i] == A[i+1] + A[i+2] + ... + A[j-1] == A[j] + A[j-1]

• ... + A[A.length - 1])`

Example 1:

Input: A = [0,2,1,-6,6,-7,9,1,2,0,1]
Output: true
Explanation: 0 + 2 + 1 = -6 + 6 - 7 + 9 + 1 = 2 + 0 + 1

Example 2:

Input: A = [0,2,1,-6,6,7,9,-1,2,0,1]
Output: false

Example 3:

Input: A = [3,3,6,5,-2,2,5,1,-9,4]
Output: true
Explanation: 3 + 3 = 6 = 5 - 2 + 2 + 5 + 1 - 9 + 4

Constraints:

• 3 <= A.length <= 50000
• -10^4 <= A[i] <= 10^4

# @lc code=start
using LeetCode

function can_three_parts_equal_sum(arr::Vector{Int})
    function can_three_parts_equal_sum(arr::AbstractVector{Int}, n::Int)
        targ = sum(arr)
        if targ % n != 0 || length(arr) == 0
            return false
        elseif n == 1
            return true
        end
        targ ÷= n
        acc = 0
        for i in 1:length(arr)
            acc += arr[i]
            targ == acc && return can_three_parts_equal_sum(@view(arr[(i + 1):end]), n - 1)
        end
        return false
    end
    return can_three_parts_equal_sum(arr, 3)
end
# @lc code=end

can_three_parts_equal_sum (generic function with 1 method)

This page was generated using DemoCards.jl and Literate.jl.