c - 按升序打印多个不同类型的数组

Question

我想根据 numbers_column3 值按升序打印多个不同类型的数组。我有两个指针数组和一个 float 组。我希望它们像 Excel 文档一样分组在一起，第一行为 a1、a2 和 a3。我每列都有三个数组。我展示的代码只是一个简单的示例。目前我的数组中有大约 20k 个值。有没有办法避免典型的冒泡排序？这将需要大量的 malloc 和 strcpy 操作。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int main(int argc, char **argv)
{
    char *q6_tag_strings_line_column1[2000] = {0};
    char *q6_nationality_strings_line_column2[2000] = {0};
    float numbers_column3[2000] = {0};

    q6_tag_strings_line_column1[0] = 
    malloc(strlen("echo")+1);

    strcpy(q6_tag_strings_line_column1[0], 
    "echo");

    q6_nationality_strings_line_column2[0] = 
    malloc(strlen("hi")+1);

    strcpy(q6_nationality_strings_line_column2[0], 
    "hi");

    numbers_column3[0] = 5;

    q6_tag_strings_line_column1[1] = 
    malloc(strlen("how")+1);

    strcpy(q6_tag_strings_line_column1[1], 
    "how");

    q6_nationality_strings_line_column2[1] = 
    malloc(strlen("are")+1);

    strcpy(q6_nationality_strings_line_column2[1], 
    "are");

    numbers_column3[1] = 7;


    q6_tag_strings_line_column1[2] = 
    malloc(strlen("you")+1);

    strcpy(q6_tag_strings_line_column1[2], 
    "you");

    q6_nationality_strings_line_column2[2] = 
    malloc(strlen("what")+1);

    strcpy(q6_nationality_strings_line_column2[2], 
    "what");

    numbers_column3[1] = 4;
    return 0;
}

预期结果是

you what 4
echo hi 5
how are 7

Answer 1

如果三个数组的元素在语义上耦合，为什么不创建一个包含 tag、nationality 和 number 的 struct 字段。这使得数据元素之间的连接变得明确，并允许使用标准库 qsort() 函数创建此类结构的数组并对其进行排序。这是一个示例程序:

#include <stdio.h>
#include <stdlib.h>

struct Data {
    char *tag;
    char *nationality;
    float number;
};

int compare_Data(const void *a, const void *b);

int main(void)
{
    struct Data my_data[] = {
        { .tag = "North America",
          .nationality = "Canadian",
          .number = 3.3 },
        { .tag = "South America",
          .nationality = "Brazilian",
          .number = 5.5 },
        { .tag = "Asia",
          .nationality = "Japanese",
          .number = 1.1 },
    };

    puts("Before sorting:");
    for (size_t i = 0; i < sizeof my_data / sizeof *my_data; i++) {
        printf("Number:      %f\n"
               "Nationality: %s\n"
               "Tag:         %s\n",
               my_data[i].number,
               my_data[i].nationality,
               my_data[i].tag);
        putchar('\n');
    }

    qsort(my_data,
          sizeof my_data / sizeof *my_data,
          sizeof *my_data,
          compare_Data);

    puts("After sorting:");
    for (size_t i = 0; i < sizeof my_data / sizeof *my_data; i++) {
        printf("Number:      %f\n"
               "Nationality: %s\n"
               "Tag:         %s\n",
               my_data[i].number,
               my_data[i].nationality,
               my_data[i].tag);
        putchar('\n');
    }
    return 0;
}

int compare_Data(const void *a, const void *b)
{
    const struct Data *da = (const struct Data *) a;
    const struct Data *db = (const struct Data *) b;

    return (da->number > db->number) - (da->number < db->number);
}

程序输出:

Before sorting:
Number:      3.300000
Nationality: Canadian
Tag:         North America

Number:      5.500000
Nationality: Brazilian
Tag:         South America

Number:      1.100000
Nationality: Japanese
Tag:         Asia

After sorting:
Number:      1.100000
Nationality: Japanese
Tag:         Asia

Number:      3.300000
Nationality: Canadian
Tag:         North America

Number:      5.500000
Nationality: Brazilian
Tag:         South America