You are going to be given an array of integers. Your job is to take that array and find an index N where the sum of the integers to the left of N is equal to the sum of the integers to the right of N. If there is no index that would make this happen, return -1
.
Let's say you are given the array {1,2,3,4,3,2,1}
:
Your function will return the index 3
, because at the 3rd position of the array, the sum of left side of the index ({1,2,3}
) and the sum of the right side of the index ({3,2,1}
) both equal 6
.
Let's look at another one.
You are given the array {1,100,50,-51,1,1}
:
Your function will return the index 1, because at the 1st position of the array, the sum of left side of the index ({1}
) and the sum of the right side of the index ({50,-51,1,1}
) both equal 1
.
You are given the array {20,10,-80,10,10,15,35}
At index 0
the left side is {}
The right side is {10,-80,10,10,15,35}
They both are equal to 0 when added. (Empty arrays are equal to 0 in this problem)
Index 0
is the place where the left side and right side are equal.
Note: Please remember that in most programming/scripting languages the index of an array starts at 0
.
An integer array of length 0 < arr < 1000
. The numbers in the array can be any integer positive or negative.
The lowest index N where the side to the left of N is equal to the side to the right of N. If you do not find an index that fits these rules, then you will return -1
.
Note:
If you are given an array with multiple answers, return the lowest correct index.
$ npm install @abranhe/codewars
const codewars = require('@abranhe/codewars');
codewars.findEvenIndex([1, 2, 3, 4, 3, 2, 1]);
//=> 3
Type: array