Question

我试图对字符串数组执行插入排序。该数组被格式化为指向char数组的指针数组。

使用以下语句声明数组：

char *wordlist[ARRAY_LEN];

使用：

传递给insertion_sort函数

insertion_sort(wordlist, num_words);

insertion_sort的功能如下所示。

void insertion_sort(char **a, int n) {
   char *key;
   int i, p;
   for(p=1; p<n; p++){    /*For every item p in the array apart from the first*/
      key = *a[p];         /*Set key to the value of p*/
      i = p-1;
      while(strcmp(*a[i], key) > 0){ /*For every item to the left of p that is larger*/
         *a[i+1] = *a[i];   /*than it move it 1 to the right*/
         i--;
      }
      *a[i+1] = key;       /*Place key in the vacated leftmost position*/
   }
}

我在编译时不断收到与指针相关的错误/警告：

word-sort.c: In function ‘insertion_sort’:
word-sort.c:21:11: warning: assignment makes pointer from integer without a cast
word-sort.c:23:7: warning: passing argument 1 of ‘strlen’ makes pointer from integer without a cast
/usr/include/string.h:399:15: note: expected ‘const char *’ but argument is of type ‘char’
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:7: warning: passing argument 1 of ‘__builtin_strcmp’ makes pointer from integer without a cast
word-sort.c:23:7: note: expected ‘const char *’ but argument is of type ‘char’
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:7: warning: passing argument 1 of ‘strlen’ makes pointer from integer without a cast
/usr/include/string.h:399:15: note: expected ‘const char *’ but argument is of type ‘char’
word-sort.c:23:7: warning: passing argument 1 of ‘__builtin_strcmp’ makes pointer from integer without a cast
word-sort.c:23:7: note: expected ‘const char *’ but argument is of type ‘char’
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:7: warning: passing argument 1 of ‘__builtin_strcmp’ makes pointer from integer without a cast
word-sort.c:23:7: note: expected ‘const char *’ but argument is of type ‘char’
word-sort.c:23:13: warning: cast to pointer from integer of different size
word-sort.c:23:7: warning: passing argument 1 of ‘__builtin_strcmp’ makes pointer from integer without a cast
word-sort.c:23:7: note: expected ‘const char *’ but argument is of type ‘char’
word-sort.c:27:15: warning: assignment makes integer from pointer without a cast

任何关于我出错的地方的想法都会很棒。

Answer 1

看看这段代码：

key = *a[p];

此处key为char*，a为char**。这意味着a[p]是char*，因此*a[p]是char。这会导致警告 - 您正在尝试将char转换为char*，这绝对令人担忧。要解决此问题，请尝试删除星标。

你的代码中存在类似的错误，你将无关的星星放入其中，这意味着你在char而不是char*传递。这解释了你得到的几乎所有警告。尝试修复此问题，看看是否能解决警告问题。

希望这有帮助！

对指针数组实现排序

1 个答案: