How is the dictionary used in the C programming language?

The C language does not have a built-in dictionary data structure, but you can simulate the functionality of a dictionary using structures and arrays.

One common approach is to use an array of structures, where each structure contains a key and a value. For example:

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

struct Dictionary {
    char key[20];
    char value[20];
};

int main() {
    struct Dictionary dict[3];

    strcpy(dict[0].key, "key1");
    strcpy(dict[0].value, "value1");

    strcpy(dict[1].key, "key2");
    strcpy(dict[1].value, "value2");

    strcpy(dict[2].key, "key3");
    strcpy(dict[2].value, "value3");

    // 根据键查找对应的值
    char searchKey[20];
    printf("请输入要查找的键：");
    scanf("%s", searchKey);

    int i;
    for (i = 0; i < 3; i++) {
        if (strcmp(dict[i].key, searchKey) == 0) {
            printf("找到了，值为：%s\n", dict[i].value);
            break;
        }
    }
    if (i == 3) {
        printf("未找到对应的值。\n");
    }

    return 0;
}

In this example, we have used a struct Dictionary to define a structure containing a key and a value. We then store multiple key-value pairs by creating an array of dicts. Values for specific keys can be found by iterating through the array.

Another approach is to use a linked list to implement a dictionary. Each node contains a key-value pair and a pointer to the next node. This method allows for flexible addition and deletion of key-value pairs, but searching requires traversing the entire linked list. Extra operations are needed to handle the insertion and deletion of nodes in the linked list.

Generally speaking, the method of implementing a dictionary in the C language can be chosen based on specific scenarios and requirements.