1013. Partition Array Into Three Parts With Equal Sum

#### QUESTION:

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: [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: [0,2,1,-6,6,7,9,-1,2,0,1]
Output: false
``````

Example 3:

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

Note:

1. `3 <= A.length <= 50000`
2. `-10000 <= A[i] <= 10000`

#### SOLUTION:

``````class Solution {
public boolean canThreePartsEqualSum(int[] A) {
int sum = IntStream.of(A).sum();
int target = 0;
if(sum%3==0) target = sum/3;
else return false;
int turn = 0,tmp =0;
for(int i = 0;i<A.length;i++){
tmp+=A[i];
if(tmp==target) {
turn++;
tmp=0;
}
}
return turn==3;
}
}
``````