hash_search.cpp

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#include <cstdlib>
#include <iostream>
 
#define MAX 6      
#define HASHMAX 5  
 
int data[MAX] = {1, 10, 15, 5, 8, 7};  
 
typedef struct list {
    int key;            
    struct list* next;  
} node,                 
    *link;              
 
node hashtab[HASHMAX];  
 
// int counter = 1;
 
int h(int key) { return key % HASHMAX; }
 
void create_list(int key) {  // Construct hash table
    link p, n;
    int index;
    n = (link)malloc(sizeof(node));
    n->key = key;
    n->next = NULL;
    index = h(key);
    p = hashtab[index].next;
    if (p != NULL) {
        n->next = p;
        hashtab[index].next = n;
    } else {
        hashtab[index].next = n;
    }
}
 
int hash_search(int key, int* counter) {  // Hash lookup function
    link pointer;
    int index;
 
    *counter = 0;
    index = h(key);
    pointer = hashtab[index].next;
 
    std::cout << "data[" << index << "]:";
 
    while (pointer != NULL) {
        counter[0]++;
        std::cout << "data[" << pointer->key << "]:";
        if (pointer->key == key)
            return 1;
        else
            pointer = pointer->next;
    }
 
    return 0;
}
 
int main() {
    link p;
    int key, index, i, counter;  // Key is the value to be found
    index = 0;
 
    // You can write the input mode here
    while (index < MAX) {  // Construct hash table
        create_list(data[index]);
        index++;
    }
 
    for (i = 0; i < HASHMAX; i++) {  // Output hash table
        std::cout << "hashtab [" << i << "]\n";
 
        p = hashtab[i].next;
 
        while (p != NULL) {
            std::cout << "please int key:";
            if (p->key > 0)
                std::cout << "[" << p->key << "]";
            p = p->next;
        }
        std::cout << std::endl;
    }
 
    while (key != -1) {
        // You can write the input mode here
        // test key = 10
        key = 10;
        if (hash_search(key, &counter))
            std::cout << "search time = " << counter << std::endl;
        else
            std::cout << "no found!\n";
        key = -1;  // Exit test
        /* The test sample is returned as:
         * data[0]:data[5]:data[15]:data[10]:search time = 3 The search is
         * successful. There are 10 in this set of data */
    }
 
    return 0;
}