hash表的创建

功能：创建一个hash table。假设有处理冲突，则採用再散列法放置该元素

代码參考《零基础学数据结构》

代码例如以下：

root@ubuntu:/mnt/shared/appbox/hash# cat hash.c
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <malloc.h>

typedef int KeyType;

typedef struct
{
        KeyType key;    /* key value */
        int hi; /*  hash counts */
}DataType;

typedef struct
{
        DataType *data;
        int tableSize;  /* hash table len */
        int curSize;    /* key value numbers */
}HashTable;

void DisplayHash(HashTable *H, int m);

/*
* H:hash table pointer
* m: hashtable len
* p: devided numbers
* hash: be hashed data (src data)
* n: number of key values
*/
void CreateHash(HashTable *H, int m, int p, int hash[], int n)
{
        int i, sum, addr, di, k = 1;/* k: ͻ/

        H->data = (DataType *)malloc(m * sizeof(DataType));

        if(H->data == NULL)
        {
                printf("H->data is NULL!\n");
                return ;
        }

        for(i=0; i<m; i++)
        {
                H->data[i].key = -1;
                H->data[i].hi = 0;
        }

        for(i=0; i<n; i++)
        {
                sum = 0;
                addr = hash[i] % p;
                di = addr;

                if(H->data[addr].key == -1)
                {
                        H->data[addr].key = hash[i];
                        H->data[addr].hi = 1;

                        printf("[line:%d] addr:%d, i=%d, key=%d\n",__LINE__, addr, i, hash[i]);
                }
                else
                {
                        do
                        {
                                di = (di + k)%m;
                                sum += 1;
                        }while((H->data[di].key != -1));
                        H->data[di].key = hash[i];
                        H->data[di].hi = sum + 1;
                        printf("[line:%d] di:%d, i=%d, key=%d\n",__LINE__, di, i, hash[i]);
                }
        }

        H->curSize = n;
        H->tableSize = m;

        DisplayHash(H, m);
}

void DisplayHash(HashTable *H, int m)
{
        int i;

        printf("hash index:     ");
        for(i=0; i<m; i++)
                printf("%-5d", i);

        printf("\n");
        printf("key value:      ");
        for(i=0; i<m;i++)
                printf("%-5d", H->data[i].key);

        printf("\n");

        printf("hash times:     ");
        for(i=0; i<m; i++)
                printf("%-5d", H->data[i].hi);

        printf("\n");
}

int main(int argc, char *argv[])
{
        int hash[] = {23, 35, 12, 56, 123, 39, 342, 90};
        int m=11, p=11, n=8, pos;

        HashTable H;

        CreateHash(&H, m, p, hash, n);

        return 0;
}
root@ubuntu:/mnt/shared/appbox/hash# 

输出结果：

root@ubuntu:/mnt/shared/appbox/hash# ./hash
[line:59] addr:1, i=0, key=23
[line:59] addr:2, i=1, key=35
[line:70] di:3, i=2, key=12
[line:70] di:4, i=3, key=56
[line:70] di:5, i=4, key=123
[line:59] addr:6, i=5, key=39
[line:70] di:7, i=6, key=342
[line:70] di:8, i=7, key=90
hash index:     0    1    2    3    4    5    6    7    8    9    10
key value:      -1   23   35   12   56   123  39   342  90   -1   -1
hash times:     0    1    1    3    4    4    1    7    7    0    0