HASH桶实现MAC地址和IP地址对应

用MAC作为KEY，来插入、查找MAC对应的IP...HASH桶深131


代码

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

struct mac_ip{
    char Mac[18];
    char Ip[16];
    struct mac_ip *next;
};
typedef struct mac_ip Mac_IP;


int hahash(const char mac[],int n)
{
    int len=strlen(mac);
    int i,sum=0;

    for(i=0;i<len;i++)
        sum+=mac[i];

    return(sum%n);
}


void insert_new(Mac_IP *tank[],char mac[],char ip[])
{
    Mac_IP *temp;
    int i,n;

    temp=(Mac_IP*)malloc(sizeof(Mac_IP));
    if(temp == NULL){
        printf("Malloc error!\n");
        exit(1);
    }

    strcpy(temp->Mac,mac);
    strcpy(temp->Ip,ip);
    temp->next=NULL;

    n=hahash(mac,131);
    if(tank[n] == NULL){
        tank[n]=temp;
    }
    else{
        temp->next=tank[n];
        tank[n]=temp;
    }
}

char *hash_search(Mac_IP *tank[],char mac[])
{
    int n;
    Mac_IP *p;

    n=hahash(mac,131);

    if(tank[n] == NULL){
        printf("No record of this MAC!\n");
        return NULL;
    }
    else{
        p=tank[n];
        while(p != NULL){
            if(strcmp(p->Mac,mac) == 0)
               return(p->Ip);
            else
                p=p->next;
        }

        printf("No record of this MAC!\n");
        return NULL;
    }
}

int main(int argc,char **argv)
{
    Mac_IP *tank[131];
    int i;
    char *ip=NULL;

    for(i=0;i<131;i++)
        tank[i]=NULL;

    insert_new(tank,"10-2F-34-25-6D-DE","192.168.10.25");
    insert_new(tank,"10-2F-34-6D-DE-25","192.168.1.126");
    insert_new(tank,"4D-25-E4-2C-62-DE","10.0.0.234");

    ip=hash_search(tank,"10-2F-34-25-6D-DE");
    if(ip != NULL){
        printf("ip:%s\n",ip);
    }

    return 0;
}