1
/**
2
 * @param {number[]} nums
3
 * @return {number}
4
 */
5
var partitionDisjoint = function (nums) {
6
  let n = nums.length;
7
  let leftMax = Array(n).fill(0),
8
    rightMin = Array(n).fill(0);
9
  let left = 0,
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    right = n - 1;
11

12
  for (let i = 0, j = n - 1; i < n, j >= 0; i++, j--) {
13
    leftMax[i] = Math.max(nums[i], !i ? -Infinity : leftMax[i - 1]);
14
    rightMin[j] = Math.min(nums[j], j === n - 1 ? Infinity : rightMin[j + 1]);
15
  }
16

17
  for (let i = 0; i < n - 1; i++) {
18
    if (leftMax[i] <= rightMin[i + 1]) {
19
      return i + 1;
20
    }
21
  }
22
};