java - 交替任命

Question

给定数组中的数字序列，返回交替排列的这些数字，即最小的数字，其次是最大的数字，其次是第二低的数字，然后是第二高的数字，依此类推。

输入:1 2 3 4 5 输出:1 5 2 4 3

输入:10 5 7 9 2 2 输出:2 10 2 9 5 7

我尝试了这样的事情，但不适合我，请帮助我。 我需要两个输出到同一个函数或方法中。

公开课测试{ int[] inputArray = { 1, 2, 3, 4, 5 };

void mergeSort(int[] array) {
    int[] helper = new int[array.length];
    mergesort(array, helper, 0, array.length - 1);
    for (int i = 0; i < array.length; i++) {
        System.out.println(array[i]);
    }
}

private void mergesort(int[] array, int[] helper, int low, int high) {
    if (low < high) {
        int middle = (low + high) / 2;
        mergesort(array, helper, low, middle);
        mergesort(array, helper, middle + 1, high);
        merge(array, helper, low, middle, high);

    }

}

private void merge(int[] array, int[] helper, int low, int middle, int high) {
    for (int i = low; i <= high; i++) {
        helper[i] = array[i];
    }
    int helperLeft = low;
    int counter = 0;
    int helperRight = middle + 1;
    int current = low;
    while (helperLeft <= middle && helperRight <= high) {
        if (counter % 2 == 0) {
            if (helper[helperLeft] <= helper[helperRight]) {
                array[current] = helper[helperLeft];
                helperLeft++;
            } else {
                array[current] = helper[helperRight];
                helperRight++;
            }

        } else {
            if (helper[helperLeft] >= helper[helperRight]) {
                array[current] = helper[helperLeft];
                helperLeft++;
            } else {
                array[current] = helper[helperRight];
                helperRight++;
            }

        }
        counter++;
        current++;
    }
    int remaining = middle - helperLeft;
    for (int i = 0; i <= remaining; i++) {
        array[current + i] = helper[helperLeft + i];
    }

}

public static void main(String[] args) {

    Solution i = new Solution();
    i.mergeSort(i.inputArray);

}

}

输出:1,4,3,5,2

Answer 1

我首先会像平常一样对数组进行排序，然后使用它以您想要的方式进行交替。

int[] toReturn = new int[inputArray.length];

Arrays.sort(inputArray);

for (int i = 0; i < inputArray.length; i+=2) {
    toReturn[i] = inputArray[i/2];
}
for (int i = 1; i < inputArray.length; i+=2) {
    toReturn[i] = inputArray[inputArray.length - i/2 - 1];
}