OddOccurrencesInArray

Lesson from https://codility.com/programmers/lessons/2-arrays/cyclic_rotation/

by evgkch

JavaScript

let solution = (N) => {
	let arr = [];
  let sum = 0;
  let number;
  N.map( (val) => {
  	if ( !arr[val] ) {
    	arr[val] = val
      sum = sum + val
    } else {
    	delete arr[val]
      sum = sum - val;
    }
  });
  return sum;
}

let N = [9, 3, 9, 3, 9, 7, 9]
console.log(solution(N))