c - 字典排序，C 语言编程，Stephen Kochan，第 10 章，练习 10

Question

我对 Stephen Kochan 编写的《C 语言编程》一书中第 10 章的练习 10 有疑问。

问题是:

Write a function called dictionarySort that sorts a dictionary, as defined in Programs 10.9 and 10.10, into alphabetical order.

虽然我认为我的排序算法没有问题，但我命名存储字符的临时变量 temp 的方式肯定有问题。我不知道我哪里错了，我已经尝试了很多次，现在我很困惑。

我的代码如下。你可以忽略这个事实，我没有写入另一个函数。当我看到我的错误时，我会做一个功能。现在，为了简单起见，我在 main 中拥有我需要的一切。

#include <stdio.h>

struct entry {
    char word[15];
    char definition[64];
};

int main (void) {
    // void dicionarySort (struct entry *dictionary[], const int entries);

    struct entry dictionary[100] = {
        { "aardvark", "a burrowing African mammal"        },
        { "ahoy",     "a nautical call of greeting"       },
        { "affix",    "to append; attach"                 },
        { "addle",    "to become confused"                },
        { "agar",     "a jelly made from seaweed"         },
        { "aerie",    "a high nest"                       },
        { "acumen",   "mentally sharp; keen"              },
        { "aigrette", "an ornamental cluster of feathers" },
        { "abyss",    "a bottomless pit"                  },
        { "ajar",     "partially opened"                  }
    };

    int i, j, entries = 10;
    struct entry temp[10];

    printf("Dictionary before sorting:\n");
    for (i = 0; i < entries; ++i)
        printf("Word: \"%s\" \t Definition: \"%s\"\n",
               dictionary[i].word, dictionary[i].definition);

    //dictionary[100] = dicionarySort(&dictionary, 10);

    for (i = 0; i < entries - 1; ++i)
        for (j = i + 1; j < entries; ++j)
            if (dictionary[i].word > dictionary[j].word) { // if previous word is higher than next word..
                temp[i] = dictionary[i];
                dictionary[i] = dictionary[j];
                dictionary[j] = temp[i];
            } // ..exchange their positions in the dictionary

    printf("\nDictionary after sorting:\n");
    for (i = 0; i < entries; ++i)
        printf("Word: \"%s\" \t Definition: \"%s\"\n",
               dictionary[i].word, dictionary[i].definition );

    printf("\n");

    return 0;
}

我得到的输出是:

Dictionary before sorting:
Word: "aardvark"         Definition: "a burrowing African mammal"
Word: "ahoy"     Definition: "a nautical call of greeting"
Word: "affix"    Definition: "to append; attach"
Word: "addle"    Definition: "to become confused"
Word: "agar"     Definition: "a jelly made from seaweed"
Word: "aerie"    Definition: "a high nest"
Word: "acumen"   Definition: "mentally sharp; keen"
Word: "aigrette"         Definition: "an ornamental cluster of feathers"
Word: "abyss"    Definition: "a bottomless pit"
Word: "ajar"     Definition: "partially opened"

Dictionary after sorting:
Word: "aardvark"         Definition: "a burrowing African mammal"
Word: "ahoy"     Definition: "a nautical call of greeting"
Word: "affix"    Definition: "to append; attach"
Word: "addle"    Definition: "to become confused"
Word: "agar"     Definition: "a jelly made from seaweed"
Word: "aerie"    Definition: "a high nest"
Word: "acumen"   Definition: "mentally sharp; keen"
Word: "aigrette"         Definition: "an ornamental cluster of feathers"
Word: "abyss"    Definition: "a bottomless pit"
Word: "ajar"     Definition: "partially opened"

如您所见，没有发生任何事情，字典也没有得到排序。我对此很困惑。我已经成功地实现了一个对数组进行排序的程序，但我不知道我应该在这里做什么。我不知道我哪里错了。如果有人能给我提示，那将对我有很大帮助!

Answer 1

与

if ( dictionary[i].word > dictionary[j].word )

您正在比较地址(dictionary[i].word 是字符串第一个字符的地址)，而不是词法值。

从这个角度来看，字典已经完美排序(因为元素位于升序内存地址)。

将其更改为:

if (strcmp(dictionary[i].word, dictionary[j].word) > 0)

它可能会起作用。