Minimum Swaps to Arrange a Binary Grid LeetCode solution in JavaScript

1
var minSwaps = function (grid) {
2
  const arr = [];
3
  let count = 0;
4

5
  for (let row of grid) {
6
    arr.push(row.lastIndexOf(1));
7
  }
8

9
  function swap(i, j) {
10
    [arr[i], arr[j]] = [arr[j], arr[i]];
11
    count++;
12
  }
13

14
  for (let i = 0; i < arr.length; i++) {
15
    // if num <= i pass b/c it's its correct spot
16
    if (arr[i] <= i) continue;
17
    let j = i;
18

19
    // scan forward looking for a num <= i
20
    while (arr[j] > i) {
21
      j++;
22
      if (j >= arr.length) return -1;
23
    }
24

25
    // swap as you move back to the right spot
26
    for (let k = j; k > i; k--) {
27
      swap(k, k - 1);
28
    }
29
  }
30
  return count;
31
};