LeetCode: Partition Array into Disjoint Intervals Solution

Approach

LeetCode's official solution covered well

Implementation

1/**
2 * @param {number[]} nums
3 * @return {number}
4 */
5var partitionDisjoint = function (nums) {
6  const [prefixMax, postfixMin] = [[], []]
7  let [max, min] = [nums[0], nums.slice(-1)[0]]
8
9  for (const num of nums) {
10    max = Math.max(max, num)
11    prefixMax.push(max)
12  }
13
14  for (const num of [...nums].reverse()) {
15    min = Math.min(min, num)
16    postfixMin.push(min)
17  }
18  postfixMin.reverse()
19
20  for (let i = 0; i < nums.length - 1; i++) {
21    if (prefixMax[i] <= postfixMin[i + 1]) {
22      return i + 1
23    }
24  }
25
26  return 0
27}