# 360 Sort Transformed Array

## 360. [Sort Transformed Array](https://leetcode.com/problems/sort-transformed-array/description/)

## 1. Question

Given a **sorted** array of integersnumsand integer valuesa,bandc. Apply a quadratic function of the form f(x) =ax2+bx+c to each elementxin the array.

The returned array must be in **sorted order**.

Expected time complexity:**O(n)**

**Example:**

```
nums = [-4, -2, 2, 4], a = 1, b = 3, c = 5,

Result: [3, 9, 15, 33]

nums = [-4, -2, 2, 4], a = -1, b = 3, c = 5

Result: [-23, -5, 1, 7]
```

## 2. Implementation

**(1) Two Pointers**

```java
class Solution {
    public int[] sortTransformedArray(int[] nums, int a, int b, int c) {
        int[] res = new int[nums.length];
        int index = a >= 0 ? nums.length - 1 : 0;
        int start = 0, end = nums.length - 1;

        while (start <= end) {
            int startNum = getNum(nums[start], a, b , c);
            int endNum = getNum(nums[end], a, b, c);

            if (a >= 0) {
                if (startNum > endNum) {
                    res[index] = startNum;
                    ++start;
                }
                else {
                    res[index] = endNum;
                    --end;
                }
                --index;
            }
            else {
                if (startNum < endNum) {
                    res[index] = startNum;
                    ++start;
                }
                else {
                    res[index] = endNum;
                    --end;
                }
                ++index;
            }
        }
        return res;
    }

    public int getNum(int x, int a, int b, int c) {
        return a * x * x + b * x + c;
    }
}
```

## 3. Time & Space Complexity

**Two Pointers**: 时间复杂度O(n), 空间复杂度O(n)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://protegejj.gitbook.io/algorithm-practice/leetcode/two-pointers/360-sort-transformed-array.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.