哈希表 

  2. #define TABLE_SIZE 200003
  4. struct Node 
  5. 	{
  6. 		char key[12], value[12];
  7. 		bool flag;
  8. 		Node () { flag = false; }
  9. } table[TABLE_SIZE];
  11. unsigned int BKDRHash(char *key)
  12. 	{
  13. 	unsigned int seed = 131;
  14. 	unsigned int hash = 0;
  15. 	while (*key)
  16. 	{
  17. 		hash = hash * seed + (*key++);
  18. 	}
  19. 		return (hash & 0x7FFFFFFF) % TABLE_SIZE;
  20. }
  22. int insert(char *key,char *value){
  23. //return 1 means OVERWRITE
  24. int pos = BKDRHash(key), m = 0,ret=0;
  25. while (table[pos].flag ) {//has word
  26. if(strcmp(table[pos].key, key) == 0){
  27. ret=1;//key match,OVER_WRITE
  28. break;
  29. }
  30. pos += 2 * (++m) - 1;
  31. if (pos >= TABLE_SIZE) pos -= TABLE_SIZE;
  32. }
  33. if(1!=ret){//over write no need this 
  34. strcpy (table[pos].key, key); 
  35. }
  36. strcpy (table[pos].value, value);
  37. table[pos].flag = true;//mark that has word
  38. return ret;
  39. }
  41. char* find(char* key){
  42. int pos = BKDRHash(key), m = 0;
  43. while (table[pos].flag) {
  44. if (strcmp(table[pos].key, key) == 0) {
  45. return table[pos].value;
  46. }
  47. else {
  48. pos += 2 * (++m) - 1;
  49. pos = (pos >= TABLE_SIZE ? pos - TABLE_SIZE : pos);
  50. }
  51. }
  52. return NULL;
  53. }





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    posted @ 2015-01-29 11:29  sober_reflection  阅读(141)  评论(0)    收藏  举报