> For the complete documentation index, see [llms.txt](https://jaywin.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jaywin.gitbook.io/leetcode/solutions/1920-build-array-from-permutation.md).

# 1920. Build Array from Permutation

<https://leetcode.com/problems/build-array-from-permutation>

## Description

Given a **zero-based permutation** `nums` (**0-indexed**), build an array `ans` of the **same length** where `ans[i] = nums[nums[i]]` for each `0 <= i < nums.length` and return it.

A **zero-based permutation** `nums` is an array of **distinct** integers from `0` to `nums.length - 1` (**inclusive**).

**Example 1:**

```
**Input:** nums = [0,2,1,5,3,4]
**Output:** [0,1,2,4,5,3]**Explanation:** The array ans is built as follows: 
ans = [nums[nums[0]], nums[nums[1]], nums[nums[2]], nums[nums[3]], nums[nums[4]], nums[nums[5]]]
    = [nums[0], nums[2], nums[1], nums[5], nums[3], nums[4]]
    = [0,1,2,4,5,3]
```

**Example 2:**

```
**Input:** nums = [5,0,1,2,3,4]
**Output:** [4,5,0,1,2,3]
**Explanation:** The array ans is built as follows:
ans = [nums[nums[0]], nums[nums[1]], nums[nums[2]], nums[nums[3]], nums[nums[4]], nums[nums[5]]]
    = [nums[5], nums[0], nums[1], nums[2], nums[3], nums[4]]
    = [4,5,0,1,2,3]
```

**Constraints:**

* `1 <= nums.length <= 1000`
* `0 <= nums[i] < nums.length`
* The elements in `nums` are **distinct**.

**Follow-up:** Can you solve it without using an extra space (i.e., `O(1)` memory)?

## ac

```java
```