Question

（第43-56行）我正在尝试为pset 5实现加载函数。我创建了一个嵌套的while循环，第一个用于迭代直到文件结束，另一个用于每个单词的结尾。我创建了char * c来存储我从字典中扫描的任何“字符串”，但是当我编译时

bool load(const char *dictionary)
{
    //create a trie data type
    typedef struct node
    {
        bool is_word;
        struct node *children[27]; //this is a pointer too!  
    }node;

    FILE *dptr = fopen(dictionary, "r");
    if(dptr == NULL)
    {
       printf("Could not open dictionary\n");
       unload();
       return false;
    }

    //create a pointer to the root of the trie and never move this (use traversal *)
    node *root = malloc(sizeof(node));
    char *c = NULL;

    //scan the file char by char until end and store it in c
    while(fscanf(dptr,"%s",c) != EOF)
    {
       //in the beginning of every word, make a traversal pointer copy of root so we can always refer back to root
       node *trav = root;

       //repeat for every word
       while ((*c) != '/0')
       {
        //convert char into array index
       int alpha = ((*c) - 97);

       //if array element is pointing to NULL, i.e. it hasn't been open yet,
        if(trav -> children[alpha] == NULL)
            {
            //then create a new node and point it with the previous pointer. 
            node *next_node = malloc(sizeof(node));
            trav -> children[alpha] = next_node; 

            //quit if malloc returns null
            if(next_node == NULL)
                {
                    printf("Could not open dictionary");
                    unload();
                    return false;
                }

            }

        else if (trav -> children[alpha] != NULL)
            {
            //if an already existing path, just go to it
            trav = trav -> children[alpha];
            }   
       }
        //a word is loaded. 
        trav -> is_word = true;

    }
}

错误：

dictionary.c:52:23: error: multi-character character constant [-
       Werror,-Wmultichar]
       while ((*c) != '/0')

我认为这意味着'/0'应该是一个单一的角色，但我不知道如何检查这个词的结尾！我还收到另一条错误消息：

dictionary.c:84:1: error: control may reach end of non-void function [-Werror,-Wreturn-type]
    }

我已经玩了一段时间了，这令人沮丧。请帮忙，如果你发现任何其他错误，我会很高兴的！

Answer 1

你想要＆＃39; \ 0＆＃39; （空终止字符）而不是＆＃39; / 0＆＃39;。另外，不要忘记在功能结束时返回一个bool！

多字符字符常量[-Werror，-Wmultichar]

1 个答案: