c - C双指针重新分配错误

Question

friend 你好:)我正在练习C编程。在这个程序中，我有一个任务来制作字符串数组。我不知道这是怎么回事...大概是关于realloc的问题，我得到的错误是_crtisvalidheappointer

#define _CRT_SECURE_NO_WARNINGS
#define MAX 100
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void readString(char **s)
{
int i = 0;
char c;
printf("\nInput string:     ");
while ((c = getchar()) != '\n')
{
    i++;
    *s = realloc(*s, i*sizeof(char*));
    if (*s == NULL) { printf("Memory allocation failed!"); exit(1); }
    (*s)[i - 1] = c;
}
*s = realloc(*s, (i + 1)*sizeof(char));
if (*s == NULL) { printf("Memory allocation failed!"); exit(1); }
(*s)[i] = '\0';
}


char **load_words()
{
int cnt=0,wordcnt=0,i=0;
char **words = NULL, *input = NULL; 
readString(&input);
while (input[cnt] != '\0' && cnt < strlen(input))
{
    words = realloc(words, ++wordcnt);//errors in second repeat of the loop
    words[wordcnt] = malloc(MAX);
    i = 0;
    while (input[cnt] != ' ')
    {
        words[wordcnt][i++] = input[cnt++];
    }
    words[wordcnt][i] = '\0';
    realloc(words[wordcnt], (i + 1)*sizeof(char));
}
realloc(words, wordcnt);
free(input);
return words;
}

void main()
{
 int i;
 char **words = NULL;
 words = load_words();
 scanf("%d", &i);
}

有人可以帮助我，告诉我我在这里做错了什么吗？此函数应返回字符串数组，但数组应为双指针(字符串矩阵)

Answer 1

你需要改变

words = realloc(words, ++wordcnt);

至

words = realloc(words, ++wordcnt * sizeof(*words));

否则，您将无法分配足够的内存。

words[wordcnt] = malloc(MAX);

这也不正确，您应该访问 words[wordcnt-1]。