// 计数排序
void CountSort(int* a, int n) {
    assert(a);
    int max = a[0], min = a[0];
    int i = 0;
    for (i = 0; i < n; i++) {
        if (a[i] > max)
            max = a[i];
        if (a[i] < min)
            min = a[i];
    }
    //范围
    int range = max - min + 1;
    //开辟计数数组
    int* count = (int*)malloc(sizeof(int) * range); 
    //没开辟成功直接错
    assert(count);
    //数组全部初始化为零
    memset(count, 0, sizeof(int) * range);
    //统计次数
    for (i = 0; i < n; i++) {
        //相对映射加加
        count[a[i] - min]++;
    }
    //通过计数数组的次数对原数组进行排序
    int j = 0;
    for (i = 0; i < range; i++) {
        while (count[i]--)
            //相对映射要回到原数组的数据+min
            a[j++] = i+min;
    }
    free(count);
    count = NULL;
}