转贴:数据结构：Hash查找

2．编写程序实现Hash表的建立、删除、插入以及查找操作。
　　程序应包含的主要功能函数有：
Hash()：计算哈希地址
InitialHash()：初始化哈希表
SearchHash()：在哈希表中查找关键字
InsertHash()：向哈希表中插入关键字
DeleteHash()：删除哈希表中某一关键字
PrintHash()：打印输出哈希表
//Hash表 #include <stdio.h> #include <stdlib.h> #include <string.h> typedef int Status; typedef int HKeyType; typedef struct { HKeyType key; int flag; } HElemType; typedef struct { HElemType *elem; int count; } HashTable; #define HASHCODE 997 #define SUCCESS 1 #define UNSUCCESS 0 #define DUPLICATE -1 #define ERROR -2 #define NONE 0 #define EXIST 1 #define DELETE -1 HKeyType Hash(HKeyType K) { return K % HASHCODE; } void InitialHash(HashTable &H) { H.elem = (HElemType *)malloc(HASHCODE * sizeof(HElemType)); memset(H.elem, NONE, HASHCODE * sizeof(HElemType)); H.count = 0; } Status SearchHash(HashTable H, HKeyType K, int &p) { p = Hash(K); while (H.elem[p].flag != NONE && K != H.elem[p].key) p++; if (K == H.elem[p].key) return SUCCESS; else return UNSUCCESS; } Status InsertHash(HashTable &H, HKeyType K) { int p = 0; if (SearchHash(H, K, p) == SUCCESS && H.elem[p].flag == EXIST) return DUPLICATE; if (p >= HASHCODE) return ERROR; H.elem[p].key = K; H.elem[p].flag = EXIST; H.count++; return SUCCESS; } Status DeleteHash(HashTable &H, HKeyType K) { int p = 0; if (SearchHash(H, K, p) != SUCCESS ) return ERROR; H.elem[p].flag = DELETE; H.count--; return SUCCESS; } Status PrintHash(HashTable H) { for (int i = 0;i < HASHCODE;i++) if (H.elem[i].flag == EXIST) printf("%d:%d/n", i, H.elem[i].key); } void menu() { printf("/n"); printf("/n* * * * * * * * * * * * * * * * * * * * * * * * * */n"); printf(" 1 ------- 查找关键字/n"); printf(" 2 ------- 插入关键字/n"); printf(" 3 ------- 删除关键字/n"); printf(" 4 ------- 打印哈希表/n"); printf(" 5 ------- 退出/n"); printf("* * * * * * * * * * * * * * * * * * * * * * * * * */n"); printf("/n"); } void menuselect(HashTable H) { int k, done = 1; int p = 0; HKeyType K; while (done) { menu(); printf("请选择一个功能: "); scanf("%d", &k); getchar(); switch (k) { case 1: { printf("/n输入查找数据: "); scanf("%d", &K); getchar(); if (SearchHash(H, K, p) != UNSUCCESS && H.elem[p].flag == EXIST)printf("数据已找到！位于：%d/n", p); else printf("数据没找到！/n"); break; } case 2: { printf("/n输入插入数据: "); scanf("%d", &K); getchar(); p = InsertHash(H, K); if (p == DUPLICATE) printf("此数据已经存在!/n"); else if (p == ERROR) printf("Hash表已满!/n"); else printf("插入成功/n"); break; } case 3: { printf("/n输入删除数据: "); scanf("%d", &K); getchar(); if (DeleteHash(H, K) == ERROR) printf("删除数据不存在!/n"); else printf("删除成功"); break; } case 4: PrintHash(H);break; case 5: done = 0; } } } int main() { HashTable H; InitialHash(H); HKeyType K; int i; int n; printf("请输入初始化数据个数："); scanf("%d", &n); getchar(); printf("请输入初始化数据："); for (i = 0;i < n;i++) { scanf("%d", &K); getchar(); if (InsertHash(H, K) == ERROR) printf("对不起，Hash表已满!/n"); } menuselect(H); return 0; }