Method 1: Simulate the Stack Operations

Intuition

We process the stream from 1 to n, and for each number, if it matches the next number in target, we push it. If not, we push and immediately pop it. We stop when all elements of target are built.

Approach

Use a pointer to track the current index in target.
For each number from 1 to n:
- If it matches target[idx], append "Push" and move to the next target.
- Otherwise, append "Push" and "Pop".
Stop when all elements of target are built.

Code

[{"language":"Python","code":"class Solution:\n    def buildArray(self, target, n):\n        res = []\n        idx = 0\n        for num in range(1, n+1):\n            if idx == len(target):\n                break\n            if num == target[idx]:\n                res.append(\"Push\")\n                idx += 1\n            else:\n                res.append(\"Push\")\n                res.append(\"Pop\")\n        return res","lang":"python","html":"<pre class=\"shiki shiki-themes github-light github-dark\" style=\"background-color:#fff;--shiki-dark-bg:#24292e;color:#24292e;--shiki-dark:#e1e4e8\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color:#D73A49;--shiki-dark:#F97583\">class</span><span style=\"color:#6F42C1;--shiki-dark:#B392F0\"> Solution</span><span style=\"color:#24292E;--shiki-dark:#E1E4E8\">:</span></span>\n<span class=\"line\"><span style=\"color:#D73A49;--shiki-dark:#F97583\">    def</span><span style=\"color:#6F42C1;--shiki-dark:#B392F0\"> buildArray</span><span style=\"color:#24292E;--shiki-dark:#E1E4E8\">(self, target, n):</span></span>\n<span class=\"line\"><span style=\"color:#24292E;--shiki-dark:#E1E4E8\">        res </span><span style=\"color:#D73A49;--shiki-dark:#F97583\">=</span><span style=\"color:#24292E;--shiki-dark:#E1E4E8\"> []</span></span>\n<span class=\"line\"><span style=\"color:#24292E;--shiki-dark:#E1E4E8\">        idx </span><span style=\"color:#D73A49;--shiki-dark:#F97583\">=</span><span style=\"color:#005CC5;--shiki-dark:#79B8FF\"> 0</span></span>\n<span class=\"line\"><span style=\"color:#D73A49;--shiki-dark:#F97583\">        for</span><span style=\"color:#24292E;--shiki-dark:#E1E4E8\"> num </span><span style=\"color:#D73A49;--shiki-dark:#F97583\">in</span><span style=\"color:#005CC5;--shiki-dark:#79B8FF\"> range</span><span style=\"color:#24292E;--shiki-dark:#E1E4E8\">(</span><span style=\"color:#005CC5;--shiki-dark:#79B8FF\">1</span><span style=\"color:#2429

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