调整数组顺序使奇数位于偶数前面

这道题,思考过,目前想的解决方案是使用双链表解决。

下面贴自己的Java代码实现:

/**
 * 题目描述:
 * 输入一个整数数组,实现一个函数来调整该数组中数字的顺序,
 * 使得所有的奇数位于数组的前半部分,所有的偶数位于数组的后半部分,
 * 并保证奇数和奇数,偶数和偶数之间的相对位置不变。
 *
 * @author ihaokun
 * @date 2019/7/14 21:00
 */
public class ReOrderArray {

    public static void main(String[] args) {
        reOrderArray(new int[]{1, 2, 3, 4, 5});
    }

    /**
     * 初步审题,感觉数组操作add、delete不方便
     * 把它变成链表再进行排序操作,最后转化为数组
     *
     * @param array 整数数组
     */
    public static void reOrderArray(int[] array) {
        // 奇数节点、偶数节点,先设置为null
        DoubleLinkedList oddNumNode = new DoubleLinkedList();
        DoubleLinkedList evenNumNode = new DoubleLinkedList();
        for (int num : array) {
            DoubleLinkedList node;
            if (num % 2 == 1) {
                node = new DoubleLinkedList(num, oddNumNode,null);
                oddNumNode.next = node;
                oddNumNode = oddNumNode.next;
            } else if (num % 2 == 0){
                node = new DoubleLinkedList(num, evenNumNode, null);
                evenNumNode.next = node;
                evenNumNode = evenNumNode.next;
            }
        }
        while (evenNumNode.prev != null){
            evenNumNode = evenNumNode.prev;
        }
        // 除去偶数首位的0
        evenNumNode = evenNumNode.next;
        // 先奇后偶
        oddNumNode.next = evenNumNode;
        while (oddNumNode.prev != null){
            oddNumNode = oddNumNode.prev;
        }
        // 除去奇数首位的0
        oddNumNode = oddNumNode.next;
        // 排序后结果:
        while (oddNumNode != null){
            System.out.println(oddNumNode.value);
            oddNumNode = oddNumNode.next;
        }
    }

    private static class DoubleLinkedList {
        private int value;
        private DoubleLinkedList prev;
        private DoubleLinkedList next;

        private DoubleLinkedList(){

        }
        private DoubleLinkedList(int value, DoubleLinkedList prev, DoubleLinkedList next){
            this.value = value;
            this.prev = prev;
            this.next = next;
        }
    }
}
原文地址:https://www.cnblogs.com/ihaokun/p/11191383.html