存储二维数组的奇怪行为？

Question

我已经包含了下面的代码，但总而言之，createMonster() 函数初始化 struct monster 字段，然后返回 struct 指针。 **readMonster() 函数应该从 input.txt 文件中读取信息并返回一个 createMonster() 指针数组。例如：monsterList[i] = createMonster(x ,y ,z)。重申一下，createMonster() 保存单个怪物的数据，并且 **readMonsters 返回一个包含其 createMonster 数据的怪物列表

问题是，当我使用第一个 for 循环循环并用 createMonster() 数据填充 monsterList[I]，然后将其打印到屏幕上时，它可以完美运行。然而，创建第二个只打印 MonsterList[I] 的 for 循环会在屏幕上打印奇怪的东西。唯一正确打印的是 int population 字段。这是下面的代码。

// omitting failed malloc checks for simplicity. Assume no mallocs failed.
#define BUFFERSIZE 50

typedef struct monster
{
   char *name;
   char *element;
   int population;
} monster; // An index

monster *createMonster(char *name, char *element, int population)
{
  // Sizeof(struct monster) for clarification.
  monster *monster = malloc(sizeof(struct monster));

  // Allocating memory for struct monster fields
  monster->name = malloc(sizeof(char) * strlen(name) + 1); // +1 null sentinel

  monster->element = malloc(sizeof(char) * strlen(element) + 1);

  // Initalizing fields based on function input parameters
  monster->name = name;
  monster->element = element;
  monster->population = population;

  // Return struct pointer
  return monster;
}

monster **readMonsters(FILE *ifp, int *monsterCount)
{
  // Initializing array of struct monster pointers
  monster **monsterList = NULL;
  // Buffer to store monster name and monster element
  char name_buffer[BUFFERSIZE], element_buffer[BUFFERSIZE];
  // Buffer to store amount of monsters in file
  int num_monsters = 0;
  // Buffer to store monstor population
  int population;
  // Iterative variable
  int i;

  // making monsterCount the address of num_monsters
  monsterCount = &num_monsters;

  // alloating monsterList and
  // simultanenously scaning the value of monsters from the file into the address of num_monsters,
  // which is monsterCount
  monsterList = malloc(sizeof(int *) * (fscanf(ifp, "%d", monsterCount)) + 1);

  // File parsing. Skipping a string based on known input.txt file structure
  fscanf(ifp, "%*s");

  // storing file information into the monsters' individual monster pointer.
  // using num_monsters for clarification and to avoid segmentation faulting

  /*  These two for loops are the issue. The first for loop prints everything to
   the screen correctly. Therefore, in this for loop, monsterList[I] holds all the
   correct createMonster() data. 
  The second for loop should just print the same information to the screen, 
  but it doesn't. What is going on with malloc?
   */

    for (i = 0; i < num_monsters; i++)
    {
      fscanf(ifp,"%s %s %d", name_buffer, element_buffer, &population);
      monsterList[i] = createMonster(name_buffer, element_buffer, population);
      // prints correctly
      printf("\n monsterList[%d]->name: %s, ->element: %s, ->population: %d\n", i, monsterList[i]->name, monsterList[i]->element, monsterList[i]->population);
    }

    for (i = 0; i < num_monsters; i++)
    {
      // does not print correctly
      printf("\n monsterList[%d]->name: %s, ->element: %s, ->population: %d\n", i, monsterList[i]->name, monsterList[i]->element, monsterList[i]->population);
    }

    return monsterList;
  }

这是打印到屏幕上的内容：

//这些都是正确的

monsterList[0]->名称：StAugustine，->元素：草，->人口：12

monsterList[1]->名称：结缕草，->元素：草，->人口：8

monsterList[2]->名称：全麦，->元素：面包，->人口：6

monsterList[3]->名称：MultiGrain，->元素：面包，->人口：10

monsterList[4]->名称：黑麦，->元素：面包，->人口：10

monsterList[5]->名称：肉桂，->元素：香料，->人口：5

monsterList[6]->名称：胡椒，->元素：香料，->人口：10

monsterList[7]->名称：南瓜，->元素：香料，->人口：30

//（第二个for循环）这些都不正确，除了来自单元格1-7的人口

monsterList[0]->名称：pʛ??，->元素：pʛ??，->人口：-641705424

monsterList[1]->名称：南瓜，->元素：香料，->人口：8

monsterList[2]->名称：南瓜，->元素：香料，->人口：6

monsterList[3]->名称：南瓜，->元素：香料，->人口：10

monsterList[4]->名称：南瓜，->元素：香料，->人口：10

monsterList[5]->名称：南瓜，->元素：香料，->人口：5

monsterList[6]->名称：南瓜，->元素：香料，->人口：10

monsterList[7]->名称：南瓜，->元素：香料，->人口：30

对任何格式错误表示歉意。

Answer 1

行：monsterList = malloc(sizeof(int *) * (fscanf(ifp, "%d", monsterCount)) + 1);是问题所在。 修复：

先使用 fscanf 读取怪物数量，然后使用该值为 monsterList 分配内存