交换功能出现分段故障

我正忙着写一行学习用的代码。这个作业我已经做了很多了，但我总是遇到同样的问题。在交换功能上，当输入字符时，我一直遇到分段错误(word &不在主"字典"字符串中的Word2)。有人能告诉我是什么原因导致了这个问题，我该如何解决它吗?对不起，如果有什么不清楚，我刚刚开始学习c++。

出现分段错误的代码:

  void swapWords(char **dict, char *word, char *word2)
{
    int i; 
    int d;
    int x;
    int y;
    char *tmp;

    while (1){  
        for(i = 0; i < MAX_NUMBER_OF_WORDS; i++)
        { 
            if(strcmp(word, dict[i]) != 0)
            {    
                if(i == MAX_NUMBER_OF_WORDS -1)
                {
                    printf("Cannot swap words. Atleast one word missing in the dictionary.n");
                    goto error;
                }
            }
            else
            {
                x = i;
                break;  
            }
        }
        for(d = 0; d < MAX_NUMBER_OF_WORDS; d++)
        { 
            if(strcmp(word2, dict[d]) != 0)
            {    
                if(d == MAX_NUMBER_OF_WORDS -1)
                {
                    printf("Cannot swap words. Atleast one word missing in the dictionary.n");
                    goto error;
                }
            }
            else
            {
                y = d;
                break;
            }
        }
        tmp = dict[x];
        dict[x] = dict[y];
        dict[y] = tmp;
        error: break;
    }
}

整个代码:

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#define MAX_NUMBER_OF_WORDS 10
void swapWords(char **dict, char *word, char *word2)
{
    int i; 
    int d;
    int x;
    int y;
    char *tmp;

    while (1){  
        for(i = 0; i < MAX_NUMBER_OF_WORDS; i++)
        { 
            if(strcmp(word, dict[i]) != 0)
            {    
                if(i == MAX_NUMBER_OF_WORDS -1)
                {
                    printf("Cannot swap words. Atleast one word missing in the dictionary.n");
                    goto error;
                }
            }
            else
            {
                x = i;
                break;  
            }
        }
        for(d = 0; d < MAX_NUMBER_OF_WORDS; d++)
        { 
            if(strcmp(word2, dict[d]) != 0)
            {    
                if(d == MAX_NUMBER_OF_WORDS -1)
                {
                    printf("Cannot swap words. Atleast one word missing in the dictionary.n");
                    goto error;
                }
            }
            else
            {
                y = d;
                break;
            }
        }
        tmp = dict[x];
        dict[x] = dict[y];
        dict[y] = tmp;
        error: break;
    }
}
void removeWord(char **dict, char *word)
{
    int i;
    int d;
    for(i = 0; i < MAX_NUMBER_OF_WORDS; i++)
    { 
        if(strcmp(dict[i], word) == 0)
        {   dict[i] = NULL;
            for(d = i+1; d < MAX_NUMBER_OF_WORDS; d++)
            { if(dict[d] == NULL)
                { dict[i] = dict[d-1];
                    dict[d-1] = NULL;
                    break;
                }
            }
            break;
        }
    }
}
void printDict(char **dict)
{
    int i = 0;
    if(dict[0] == NULL)
    {
        printf("The dictionary is empty.n");
    }
    else{
    while (dict[i] != NULL)
    {
        printf("- %sn", dict[i]);
        i++;
    }
    }
}
void addWord(char **dict, char *word)
{
    int d;
    char *word1;
            for(d = 0; d < MAX_NUMBER_OF_WORDS; d++)
            {
                if (dict[d] == NULL)
                {           
                word1 = (char*) malloc(sizeof(char)*(strlen(word) + 1));
                strcpy(word1, word);
                dict[d] = word1;
                break;
                }
            }
}
int numberOfWordsInDict(char **dict)
{
    int i = 0;
    int d;
    for (d = 0; d < MAX_NUMBER_OF_WORDS; d++){
    if(dict[d] != NULL)
    {
        i++;
    }
}
    return i;
}
int main()
{
    char *dict[MAX_NUMBER_OF_WORDS] = {};
    char word[36];
    char word2[36];
    char c;
    int i;
    while(printf("Command (a/p/r/s/q): "))
    {
    scanf(" %c", &c);
    switch (c){
    case 'p':   printDict(dict);
                break;
    case 'a':   printf("Enter a word: ");
                scanf("%s", word);
                addWord(dict, word);
                break;
    case 'n':   i = numberOfWordsInDict(dict);
                printf("%dn", i);
                break;
    case 'r':   printf("Remove a word: ");
                scanf("%s", word);
                removeWord(dict, word);
                break;
    case 's':   printf("Swap two words:n");
                printf("Enter first word: ");
                scanf("%s", word);
                printf("Enter second word: ");
                scanf("%s", word2);
                swapWords(dict, word, word2);
                break;
    case 'q':   return 0;
            }
        }
}