Minimum Operations to Make Array Equal to Target
<p>You are given two positive integer arrays <code>nums</code> and <code>target</code>, of the same length.</p>

<p>In a single operation, you can select any subarray of <code>nums</code> and increment each element within that subarray by 1 or decrement each element within that subarray by 1.</p>

<p>Return the <strong>minimum</strong> number of operations required to make <code>nums</code> equal to the array <code>target</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">nums = [3,5,1,2], target = [4,6,2,4]</span></p>

<p><strong>Output:</strong> <span class="example-io">2</span></p>

<p><strong>Explanation:</strong></p>

<p>We will perform the following operations to make <code>nums</code> equal to <code>target</code>:<br />
- Increment&nbsp;<code>nums[0..3]</code> by 1, <code>nums = [4,6,2,3]</code>.<br />
- Increment&nbsp;<code>nums[3..3]</code> by 1, <code>nums = [4,6,2,4]</code>.</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">nums = [1,3,2], target = [2,1,4]</span></p>

<p><strong>Output:</strong> <span class="example-io">5</span></p>

<p><strong>Explanation:</strong></p>

<p>We will perform the following operations to make <code>nums</code> equal to <code>target</code>:<br />
- Increment&nbsp;<code>nums[0..0]</code> by 1, <code>nums = [2,3,2]</code>.<br />
- Decrement&nbsp;<code>nums[1..1]</code> by 1, <code>nums = [2,2,2]</code>.<br />
- Decrement&nbsp;<code>nums[1..1]</code> by 1, <code>nums = [2,1,2]</code>.<br />
- Increment&nbsp;<code>nums[2..2]</code> by 1, <code>nums = [2,1,3]</code>.<br />
- Increment&nbsp;<code>nums[2..2]</code> by 1, <code>nums = [2,1,4]</code>.</p>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length == target.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i], target[i] &lt;= 10<sup>8</sup></code></li>
</ul>
Stack; Greedy; Array; Dynamic Programming; Monotonic Stack
function minimumOperations(nums: number[], target: number[]): number {
    const n = nums.length;
    let f = Math.abs(target[0] - nums[0]);
    for (let i = 1; i < n; ++i) {
        const x = target[i] - nums[i];
        const y = target[i - 1] - nums[i - 1];
        if (x * y > 0) {
            const d = Math.abs(x) - Math.abs(y);
            if (d > 0) {
                f += d;
            }
        } else {
            f += Math.abs(x);
        }
    }
    return f;
}
