IP trie树接口

自己实现了一个IP trie树接口.

在这里保存一下，方便备份以后使用，同时欢迎纠错和交流，希望有大神能指教更高效的算法.

1.头文件如下(iptrie.h)

 #ifndef _IP_TRIE_H_
 #define _IP_TIRE_H_

 #define SPLIT_SIGN "."
 #define IP_BINARY_LEN 32

 typedef struct ip_trie_node
 {
     struct ip_trie_node *child[]; //two child node
 }ip_trie_node;

 ip_trie_node *create_iptrie_node();

 void insert_iptrie_node(ip_trie_node *root,char ip[]);

 int select_iptrie_node(ip_trie_node *root,char ip[]);

 #endif

2.c文件如下(iptrie.c)

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include "iptrie.h"

 /*
  *name: itobinary
  *
  *param:
  * num: orignal number; binary_str: dest string; index: the binary str copy index
  *
  *return:
  * void
  */
 void itobinary(int num,char binary_str[],int index)
 {
     if(binary_str == NULL)
     {
         return;
     }

     int i,bit = 0x01;
     for(i = ; i < ; i++)
     {//conver integer to 8 bit binary str
         if((num & bit) != )
         {//oprater & is lower than !=
             binary_str[index +  - i] = '';
         }
         else
         {
             binary_str[index +  - i] = '';
         }

         bit <<= ; //bit * 2
     }
 }

 /*
  *name: convert_ip_binary
  *
  *param:
  * ip:orign ip string; binary_str:dest binary string
  *
  *return:
  * void
  */
 void convert_ip_binary(char ip[],char binary_str[])
 {
     if(ip == NULL || binary_str == NULL)
     {
         return;
     }

     /*为确保正确性在进行转换之前可以进一步进行IP格式校验*/

     char *ip_sub = NULL;
     int i,index =;

     ip_sub = strtok(ip,SPLIT_SIGN); //slit ip by .

     itobinary(atoi(ip_sub),binary_str,index);

     for(i = ; i < ; i++)
     {//need to ip legal detect to pretend error
         ip_sub = strtok(NULL,SPLIT_SIGN);

         index += ;
         itobinary(atoi(ip_sub),binary_str,index);
     }

 }

 /*
  *name: create_iptrie_node
  *
  *return:
  * new ip trie node
  */
 ip_trie_node *create_iptrie_node()
 {
     ip_trie_node *node = (ip_trie_node *)calloc(,sizeof(ip_trie_node));

     if(node == NULL)
     {
         perror("create ip trie node error -- calloc");
     }
     else
     {
         node->child[] = NULL;
         node->child[] = NULL;
     }

     return node;
 }

 /*
  *name: insert_iptrie_node
  *
  *param:
  * root: trie root; ip: orignal ip string
  *
  *return:
  * void
  *
  *notice:
  * this function call strtok it will change input ip
  * so if input ip need to use at other position
  * you shold input a copy of ip
  */
 void insert_iptrie_node(ip_trie_node *root,char ip[])
 {
     if(root == NULL)
     {
         printf("trie have not init\n");

         return;
     }

     if(ip == NULL)
     {
         return;
     }

     char binary_str[IP_BINARY_LEN + ];
     int i,child_index;

     memset(binary_str,,IP_BINARY_LEN + );

     convert_ip_binary(ip,binary_str); //to binary string

     for(i = ; i < IP_BINARY_LEN; i++)
     {
         child_index = binary_str[i] - ''; //child is 0 or 1
         if(root->child[child_index] == NULL)
         {
             root->child[child_index] = create_iptrie_node();
         }

         root = root->child[child_index];
     }
 }

 /*
  *name: select_iptrie_node
  *
  *param:
  * root: trie root; ip: orignal ip string
  *
  *return:
  * 0 :not find; 1:find
  *
  *notice:
  * this function call strtok it will change input ip
  * so if input ip need to use at other position
  * you shold input a copy of ip
  */
 int select_iptrie_node(ip_trie_node *root,char ip[])
 {
     if(root == NULL)
     {
         printf("trie have not init\n");
         return ;
     }

     if(ip == NULL)
     {
         return ;
     }

     int i;
     char binary_str[IP_BINARY_LEN + ];

     memset(binary_str,,IP_BINARY_LEN + );

     convert_ip_binary(ip,binary_str); //to binary string

     int child_index;
     for(i = ; i < IP_BINARY_LEN; i++)
     {
         child_index = binary_str[i] - '';

         if(root->child[child_index] == NULL)
         {
             return ;
         }

         root = root->child[child_index];
     }

     return ;
 }

3.main.c如下(测试程序)

 #include <stdio.h>
 #include <stdlib.h>

 #include "iptrie.h"

 int main()
 {
     char sip[];
     char dip[];
     int i = ;
     int isfind = ;
     ip_trie_node *root = create_iptrie_node();

     while()
     {
         printf("insert a ip:\n");
         scanf("%s",sip);
         insert_iptrie_node(root,sip);

         printf("query a ip:\n");
         scanf("%s",dip);
         isfind = select_iptrie_node(root,dip);
         if(isfind == )
         {
             printf("find\n");
         }
         else
         {
             printf("not find\n");
         }
     }
 }

4.Makefile (linux下编译)

CC = gcc
CFLAG = -g

INC = -I./

target:Iptrie

Iptrie:iptrie.o main.c
    $(CC) $(CFLAG) $(INC) -o $@  $^

iptrie.o:iptrie.c
    $(CC) -c $<

clean:
    rm *.o Iptrie