LeetCode-977 Squares of a Sorted Array Solution (with Java)

1. Description:

Notes: 

2. Examples:

3.Solutions:

/**
 * Created by sheepcore on 2019-02-12
 */
class Solution {
    public int[] sortedSquares(int[] A) {
       int length = A.length;
        int[] B = new int[length];

        // 原数组全为正数
        if (A[0] >= 0) {
            for (int i = 0; i < length; i++)
                B[i] = (int) Math.pow(A[i], 2.0);
        }

        // 原数组全为负数
        else if (A[length - 1] < 0)
            for (int i = 0; i < length; i++)
                B[i] = (int) Math.pow(A[length - i - 1], 2);
        else {

            int tail = length - 1;
            int head = 0, count = 0;
            int num;
            // 左右摇摆法找最大绝对值数！然后平方装入数组中。
            while (head <= tail) {
                num = A[head];
                if (Math.abs(num) > Math.abs(A[tail])) {
                    B[length - count - 1] = (int) Math.pow(num, 2);
                    head++;

                } else {
                    B[length - count - 1] = (int) Math.pow(A[tail], 2);
                    tail--;
                }
                count++;
            }
        }
        return B;
    }
}