905. Sort Array By Parity

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題目敘述

Given an integer array nums, move all the even integers at the beginning of the array followed by all the odd integers.

Return any array that satisfies this condition.

Example 1

Input: nums = [3,1,2,4] Output: [2,4,3,1] Explanation: The outputs [4,2,3,1], [2,4,1,3], and [4,2,1,3] would also be accepted.

Example 2

Input: nums = [0] Output: [0]

解題思路

• 用 for 迴圈遍歷 int[] nums
• 利用 deque 資料結構
  • 若遇到數值為偶數的，利用 addFirst() 至於 deque 前面
  • 若遇到數值為奇數的，利用 addLast() 至於 deque 後面
• 最後將 deque 轉成 int[] 輸出

Solution

import java.util.Deque;
import java.util.LinkedList;

class Solution {
    public int[] sortArrayByParity(int[] nums) {
        Deque<Integer> dq = new LinkedList<>();

        for(int num : nums){
            if(num % 2 == 0){
                dq.addFirst(num);
            }else{
                dq.addLast(num);
            }
        }

        return dq.stream().mapToInt(Integer::intValue).toArray();
    }
}