如何在 Gtree (glib) 上搜索元素？

Question

所以我有一个 Gtree 每个节点都是一个结构：

typedef struct user {
    int id;
    char username[256]; 
    int post_count; 
    char short_bio[16384]; 
    int reputation;
}*USER;

还有一个 GTree：

GTree* users;

我现在想做的是，一旦我有了一个 ID，我想在我的 Gtree* users 上搜索，看看是否有一个与那个 ID 相同的用户我通过了，如果有我想增加 post_count 变量并停止搜索。

示例：

I pass to the function id=3 and it searches on the GTree for 
a User with id=3 and increments 1 on post_count, using GLIB; 

void increment (GTree* a,int id);

Answer 1

根据文档，g_tree_lookup 似乎是您需要的功能。它会根据传递的 gconstpointer key:

找到一个值

g_tree_lookup ()
gpointer
g_tree_lookup (GTree *tree,
               gconstpointer key);
Gets the value corresponding to the given key. Since a GTree is automatically balanced as key/value pairs are added, key lookup is O(log n) (where n is the number of key/value pairs in the tree).

代码类似于：

  void increment (GTree* a, int id)
  {
      gpointer ptr = g_tree_lookup (a,  &id);   // search the tree and find the value

      struct user *u = (struct user *) ptr; // cast the `gpointer ` to your pointer to your value 

      if(u){
          u->post_count++;  // increment the post_count
      }
  }

让我知道这是否适合你。

如何在 Gtree (glib) 上搜索元素？

How to search for an element on a Gtree (glib)?

c

glib

data-structures