Algorithms: 散列表

/*--------------------------------------------------------------------------------------- * Project: HashQuad.h * Name: zwp * Date: 2014.3 *----------------------------------------------------------------------------------------*/#ifndef HASHQUAD_H_#define HASHQUAD_H_typedef int ElementType;typedef unsigned int Index;typedef Index Position;struct HashTbl;typedef struct HashTbl* HashTable;/*** 初始化哈希表*/HashTable InitializeTable(int TableSize);/*** 遍历散列表*/void Traverse(HashTable H);/*** 销毁哈希表*/void DestroyTable(HashTable H);/*** 寻找元素*/Position Find(ElementType Key, HashTable H);/*** 插入元素*/void Insert(ElementType Key, HashTable H);/*** 删除元素 */ElementType Retrive(Position P, HashTable H);/*** 二次散列*/HashTable Rehash(HashTable H);#endif

/*-------------------------------------------------------------------------- * Project: HashQuad.cpp * Name: zwp * Date: 2014/3 *---------------------------------------------------------------------------*/#include "HashQuad.h"#include <stdlib.h>#include <stdio.h>#include <malloc.h>/*** 表示三种状态， 已在, 空， 删除 */enum KindOfEntry { Legitimate, Empty,  Deleted };#define MinTableSize 10struct HashEntry{ElementType  Element;enum KindOfEntry Info;};typedef struct HashEntry Cell;struct HashTbl{Cell *TheCells;int TableSize;};/*** 判断是不是素数*/bool isPrime(int number){number = abs(number);if(number == 0 || number == 1)return true;int divisor;for(divisor = number/2; number % divisor != 0; -- divisor);return divisor == 1;}/*** 产生素数*/static int NextPrime(int num){for(int index = num; index < 10000; ++ index){if(num)return num;}return num;}/*** 散列函数*/int Hash(ElementType key, int size){return (key % size);}/*** 初始化散列表*/HashTable InitializeTable(int TableSize){HashTable H;inti;if(TableSize < MinTableSize){printf("Table size too small....\n");return NULL;}/*** Allocate Table*/H = (HashTbl*)malloc(sizeof(struct HashTbl));if(H == NULL)printf("Out of space.....\n");H->TableSize = NextPrime(TableSize);/* Allocate array of Cells */H->TheCells = (Cell*)malloc(sizeof(Cell) * H->TableSize);if(H->TheCells == NULL)printf("Out of space....\n");/* Set all number state is ‘Empty’ */for(i = 0; i < H->TableSize; i ++)H->TheCells[i].Info = Empty;return H;}/*** 寻找元素*/Position Find(ElementType Key, HashTable H){Position CurrentPos;intCollisionNum = 0;CurrentPos = Hash(Key, H->TableSize);while(H->TheCells[CurrentPos].Info != Empty && H->TheCells[CurrentPos].Element != Key){/* Probably need strcmp ReHash */CurrentPos += 2 * (++CollisionNum) - 1;if(CurrentPos >= H->TableSize)CurrentPos -= H->TableSize;}return CurrentPos;}void Insert(ElementType Key, HashTable H){Position Pos;Pos = Find(Key, H); /* 若要插入的元素未存在 */if(H->TheCells[Pos].Info != Legitimate){H->TheCells[Pos].Info = Legitimate;H->TheCells[Pos].Element = Key;}}/*** 删除元素 */ElementType Retrive(Position P, HashTable H){ElementType number = 0;if(H->TheCells[P].Info == Legitimate){number = H->TheCells[P].Element;H->TheCells[P].Info = Empty;}return number;}/*** 遍历散列表*/void Traverse(HashTable H){if(H->TheCells == NULL)printf("The Hash Table is Empty...\n");for(int index = 0; index < H->TableSize; ++ index)printf("%d  \n", H->TheCells[index].Element);}/*** 销毁哈希表*/void DestroyTable(HashTable H){free(H->TheCells);free(H);}/*** 二次散列*/HashTable Rehash(HashTable H){int i, OldSize;Cell* OldCells;OldCells = H->TheCells;OldSize = H->TableSize;/* Get a new, empty table  */H = InitializeTable(2 * OldSize);/* Scan through old table, reinsering into new */for(i = 0; i < OldSize; ++ i)if(OldCells[i].Info == Legitimate)Insert(OldCells[i].Element, H);free(OldCells);return H;}

/*-------------------------------------------------------------------- * Project: Main.cpp * Name: zwp * Date: 2014/3 *--------------------------------------------------------------------*/#include "HashQuad.h"#include <stdio.h>#include <stdlib.h>int main(int argc, char* argv[]){HashTable H;H = InitializeTable(100);for(int i = 0; i < 100; ++ i)Insert(i+2, H);Traverse(H);system("pause");}