pairs

by hamix

JavaScript

let arr1 = [1, 2, 3, 9];
let arr2 = [-1, 2, -3, 4];

function find(arr, sum) {
  let aset = new Set();
  let isFound = false;
  arr.forEach(function(c) {
    if (aset.has(c)) {
      isFound = true;
      return;
    }

    aset.add(sum - c);
    console.log(sum - c);
  });
  return isFound;
}
console.log(find(arr2, 1));