[LeetCode] Problem 977 - Squares of a Sorted Array

Posted on | In ,

Given an array of integers A sorted in non-decreasing order, return an array of the squares of each number, also in sorted non-decreasing order.

Example

No.1

Input: [-4,-1,0,3,10]

Output: [0,1,9,16,100]

No.2

Input: [-7,-3,2,3,11]

Output: [4,9,9,49,121]

Note

1 <= A.length <= 10000
-10000 <= A[i] <= 10000
A is sorted in non-decreasing order.

Code

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
public int[] sortedSquares(int[] A) {
    int n = A.length;
    int[] result = new int[n];
    int right = 0;

    while (right < n && A[right] < 0)
        right++;

    int left = right - 1;
    int i = 0;

    while (left >= 0 && right < n) {
        if (A[left] * A[left] < A[right] * A[right]) {
            result[i++] = A[left] * A[left];
            left--;
        } else {
            result[i++] = A[right] * A[right];
            right++;
        }
    }

    while (left >= 0) {
        result[i++] = A[left] * A[left];
        left--;
    }

    while (right < n) {
        result[i++] = A[right] * A[right];
        right++;
    }

    return result;
}