JAVA实现：一个数组有2n个元素，其中有n个奇数、n个偶数，数组无序，写一个算法使得奇数位置放置奇数，偶数位置放置偶数

 

 

public class JiAndOu {

    public static void main(String[] args) {
        JiAndOu main = new JiAndOu();
        main.doAction();
    }

    private void doAction() {
        int[] nums = {1,2,1,2,1,1,1,2,2,2,2,1,1,2,2,2,2,1,1,1};
        //int[] nums = {1,1,1,2,2,2};
        sort(nums);

        for (Integer i : nums) {
            System.out.println(i);
        }

    }

    private void sort(int[] nums) {

        int idxj = 1;
        int idxo = 0;

        for (int i = 0; i < nums.length; i++) {


            int curr = nums[i];

            if (curr % 2 == 1) {
                if (i % 2 == 1) {
                    idxj = Math.max(idxj, i + 2);
                } else {
                    while (nums[i] % 2 == 1) {
                        swap(nums, i, idxj);
                        idxj += 2;
                    }
                }
            } else {
                if (i % 2 == 0) {
                    idxo = Math.max(idxo, i + 2);
                } else {
                    while (nums[i] % 2 == 0) {
                        swap(nums, i, idxo);
                        idxo += 2;
                    }
                }
            }


        }



    }


    private void swap(int[] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }
}