哈希表问题 字符常量和变量的区别

wujiajia

1. #include <stdio.h>
   
2. #include <string.h>
   
3. #include "hashit.h"
   
4. #include "hfunctions.h"
   
5. #define A 0
   
6. hash_t hashtab;
   
7. int cmp(const void *p1, const void *p2) { return strcmp((const char * ) p1, (const char * ) p2); }
   
8. int init() {
   
9.     int i;
   
10. #if A
    
11.   char key[][10]={"name","address","phone","door","city","sx","major"};
    
12.   char value[][15]={"netboy","china","263788","110#","guangzhou","male","information"};
    
13. #else
    
14.   char *key[]={"name","address","phone","door","city","sx","major"};
    
15.   char *value[]={"netboy","china","263788","110#","guangzhou","male","information"};
    
16. #endif
    
17.   char  *pkey;
    
18.   char *pval;
    
19.   for(i=0;i<2;i++) {
    
20.    /* pkey=(char*)malloc(strlen(key[i])+1); pval=(char*)malloc(strlen(value[i])+1); strcpy(pkey,key[i]); strcpy(pval,value[i]); */
    
21.     //hashit_insert(hashtab,pkey,pval);
    
22.     hashit_insert(hashtab,key[i],value[i]);
    
23.    }
    
24.   printf("A name=%s\n",(char*)(hashit_lookup(hashtab,(char*)"name")));
    
25.   printf("A address=%s\n",(char*)(hashit_lookup(hashtab,(char*)"address")));
    
26. }
    
27. int main()
    
28. {
    
29.   hashtab = hashit_create(5, 7,NULL,cmp,CHAIN_H);
    
30.     init();
    
31.   printf("begin...\n");
    
32.   //此处如果为空 是因为hash中保存的为指针
    
33.   printf("B name=%s\n",(char*)(hashit_lookup(hashtab,(char*)"name")));
    
34.   printf("B phone=%s\n",(char*)(hashit_lookup(hashtab,(char*)"address")));
    
35.   hashit_destroy(hashtab);
    
36.   return 0;
    
37. }

复制代码

结果是 如果定义的A=1：
A name=(null)
A address=china
begin...
B name=(null)
B phone=(null)
反之：
A name=netboy
A address=china
begin...
B name=netboy
B phone=china

wujiajia

求解啊