插入排序，冒泡排序，归并排序, 稳定排序

#include <stdio.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>
#define swap(a, b) ({\
        __typeof(a) __temp = a;\
        a = b; b = __temp;\
})
#define TEST(arr, n, func, args...) {\
        int *num = (int *)malloc(sizeof(int) * n);\
        memcpy(num, arr, sizeof(int) * n);\
        printf("\n");\
        output(num, n);\
        printf(#func);\
        func(args);\
        output(num, n);\
        free(num);\
}
void insert_sort(int *num, int n) {
        for (int i = 1; i < n; ++i)
                for (int j = i; j > 0 && num[j] > num[j - 1]; --j) {
                        swap(num[j], num[j - 1]);
                }
        return ;
}

void bubble_sort(int *num, int n) {
        int k = 0;
        for (int i = 0; i < n - 1 && !k; ++i) {
                k = 0;
                for (int j = 0; j < n - i; ++j ) {
                        num[j] < num[j + 1] && swap(num[j], num[j + 1]);
                        num[j] < num[j + 1] && (k = 1);
                }
        }
        return ;
}

void merge_sort(int *num, int l, int r) {
        if (r - l <= 1) {
                r - l == 1 && num[l] > num[r] && swap(num[l], num[r]);
               return ;
        }
        int mid = (l + r) >> 1;
        merge_sort(num, l, mid);
        merge_sort(num, mid + 1, r);
        int *temp = (int *)malloc(sizeof(int) * (r - l + 1)), lt = l, rt = mid + 1, k = 0;
        while (lt <= mid || rt <= r) {
                if (rt > r && lt <= mid || lt <= mid && num[lt] <= num[rt]) temp[k++] = num[lt++];
                if (lt > mid && rt <= r || rt <= r && num[lt] >= num[rt]) temp[k++] = num[rt++];
        }
        memcpy(num + l, temp, sizeof(int) * (r - l + 1));
        free(temp);
        return ;
}

void output(int *num, int n) {
        printf("\n");
        for (int i = 0; i < n; i++) printf("%d", num[i]), printf(", ");
}

void input(int *num, int n) {
        for (int i = 0; i < n; ++i) num[i] = rand() % 100;
}

int main() {
        srand(time(0));
#define MAX 20
        int arr[MAX], oj = rand() % 3;
        input(arr, MAX); output(arr, MAX);
        for (int i = 0; i < MAX; ++i, oj = rand() % 3)
        switch (oj) {
                case 0: TEST(arr, MAX, insert_sort, num, MAX);
                        break;
                case 1: TEST(arr, MAX, bubble_sort, num, MAX);
                        break;
                case 2: TEST(arr, MAX, merge_sort, num, 0, MAX - 1);
        }
#undef MAX
        return 0;
}