c - 为什么我的字典没有正确计算出现次数？

Question

我正在将单词输入二叉树并计算它们出现的次数。

这是文本文件:http://pastebin.com/FY9ZTQX6

到目前为止，这是我的代码。这一切都发生在 insert() 函数中:

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

/*
Name: Marcus Lorenzana
Assignment: Final
*/

/*binary tree struct to hold left and right node
as well as the word and number of occurrences*/
typedef struct node
{
    char *word;
    int count;
    struct node *left;
    struct node *right;
}
node;

//,.:;-
int punctuation[4] = {0};

/*Function Prototypes*/
void insert(node ** dictionary, node * entry);
char* readFile(char* filename);
void printDictionary(node * tree);
void printPunctuation(); 
void toLower(char** word);
char *replace(char *st, char *orig, char *repl);; 



int main()
{

    char *word;
    char* filecontents = readFile("data.txt");
    FILE *fp = fopen("data.txt","r");


    //create dictionary node
    node *dictionary;
    node *entry;

    //read words and punctuation in from the text file
    word = strtok (filecontents, " \n");

    dictionary = NULL;

    //create and add lowercase entries into the dictionary
    //by calling insert function 
    while (word != NULL)
    {

        //store punctuation in it's own array of occurrences
        //since there are only 4 to watch out for
        if (word[0]==',') {
            punctuation[0]++; 
            word = strtok (NULL, " \n");
        } else if (word[0]=='.')  {
            punctuation[1]++; 
            word = strtok (NULL, " \n");
        }
         else if (word[0]==';')  {
            punctuation[2]++; 
            word = strtok (NULL, " \n");
        }
         else if (word[0]=='-')  {
            punctuation[3]++; 
            word = strtok (NULL, " \n");
        } 
         else if (word[0]=='$') {
            break;
        }
        //use binary tree to store unique words
         else {
            //convert word to lowercase first, so capital words
            //won't have precedence
            word = strlwr(word);
            //create entry node and call insert with dictionary being call by reference
            //so that is is mutable
            entry = (node *) malloc(sizeof(node));
            entry->left = entry->right = NULL;
            entry->word = malloc(sizeof(char)*(strlen(word)+1));
            entry->word = word;
            insert(&dictionary,entry);
            word = strtok (NULL, " \n");
        }

    }
    //print the dictionary of words and their number of occurrences
    printDictionary(dictionary);
    //print the punctuation and their number of occurrences
    printPunctuation();


    //find word to be replaced

    int found = 0;
    char buffer[250];
    char src[50] , dest[50];
    while(fgets(buffer , sizeof(buffer) , fp) != NULL)
    {
        if(strchr(buffer , '<'))
        {
            found++;
            break;
        }
    }
    if(found)
    {
        fscanf(fp , "%s < %s" , src , dest);
    }

    //example of replace()
    FILE *fout = fopen("newdata.txt","w");
    filecontents = readFile("data.txt");

    fprintf(fout,"%s",replace(filecontents,src,dest));

    fclose(fout);
    fclose(fp);

    return 0;
}

/*inserts an entry into the dictionary in lexicographical order*/
void insert(node ** dictionary, node * entry)
{
    //if there are no entries, set dictionary point
    //to new one and set count to 1 
    if(!(*dictionary))
    {
        *dictionary = entry;
        (*dictionary)->count=1;
        return;
    }

    //compare word to see if it of higher
    //or lower alphabetical order
    int result = strcmp(entry->word,(*dictionary)->word);

    //if it is lower, place on the left
    if(result<0)
    {

        insert(&(*dictionary)->left, entry);
        (*dictionary)->count=1; 


    }
    //if it is higher, place on the right
    if(result>0)
    {

        insert(&(*dictionary)->right, entry);
        (*dictionary)->count=1; 


    }
    //if it is equal, don't create a new entry but update the count
    if(result == 0)
    {
        (*dictionary)->count++; 
    }

}

/*put file contents in string for strtok*/
char* readFile(char* filename)
{
    FILE* file = fopen(filename,"r");
    if(file == NULL)
    {
        return NULL;
    }

    fseek(file, 0, SEEK_END);
    long int size = ftell(file);
    rewind(file);

    char* content = calloc(size + 1, 1);

    fread(content,1,size,file);

    return content;
}

/*prints the dictionary in lexicographical order
and number of occurrences for each word*/
void printDictionary(node * dictionary)
{
    //traverse dictionary in lexicographical order
    if(dictionary->left)
    {
        printDictionary(dictionary->left);
    }
    //print word and number of occurrences
    printf("%s\n",dictionary->word);
    printf("=%d\n",dictionary->count); 

    if(dictionary->right)
    {
        printDictionary(dictionary->right);
    }
}

/*prints the punctuation and number of occurrences*/
void printPunctuation(){
    //,.:;-
    printf("\n, = %d",punctuation[0]); 
    printf("\n. = %d",punctuation[1]); 
    printf("\n; = %d",punctuation[2]); 
    printf("\n- = %d",punctuation[3]); 

}

/*replace word*/
char *replace(char *st, char *orig, char *repl)
{
    static char buffer[2000];
    char *ch;
    if (!(ch = strstr(st, orig)))
        return st;
    strncpy(buffer, st, ch-st);
    buffer[ch-st] = 0;
    sprintf(buffer+(ch-st), "%s%s", repl, ch+strlen(orig));
    return buffer;
}

这是我得到的输出:http://pastebin.com/8qSPQkiM

Answer 1

我将从改变这个开始:

        entry->word = malloc(sizeof(char)*(strlen(word)+1));
        entry->word = word;

为此:

        entry->word = malloc(sizeof(char)*(strlen(word)+1));
        strcpy(entry->word, word);

就像现在一样，您正在泄漏内存并存储最终无效的堆栈变量指针。您的代码还有其他问题，但这可能是您面临的最直接的问题。

接下来，在 insert() 中，您错误地重置了中间节点上的计数器。这:

//if it is lower, place on the left
if(result<0)
{
    insert(&(*dictionary)->left, entry);
    (*dictionary)->count=1; // <=== SHOULD NOT BE HERE
}

//if it is higher, place on the right
if(result>0)
{
    insert(&(*dictionary)->right, entry);
    (*dictionary)->count=1; // <=== SHOULD NOT BE HERE
}

//if it is equal, don't create a new entry but update the count
if(result == 0)
{
    (*dictionary)->count++; 
}

应该是这样的:

if(result<0)
{
    insert(&(*dictionary)->left, entry);
}
else if (result>0)
{
    insert(&(*dictionary)->right, entry);
}
else
{   // found it. update the count
    (*dictionary)->count++; 
}