ตารางแฮชเป็นโครงสร้างข้อมูลที่ใช้เก็บคู่คีย์-ค่า ฟังก์ชันแฮชถูกใช้โดยตารางแฮชเพื่อคำนวณดัชนีลงในอาร์เรย์ที่จะแทรกหรือค้นหาองค์ประกอบ
นี่คือโปรแกรม C ++ ที่ใช้เชื่อมโยงตารางแฮชกับรายการที่เชื่อมโยงโดยลำพัง
อัลกอริทึม
สำหรับการแทรก:
Begin Declare Function Insert(int k, int v) int hash_v = HashFunc(k) HashTableEntry* p = NULL HashTableEntry* en = ht[hash_v] while (en!= NULL) p = en en= en->n if (en == NULL) en = new HashTableEntry(k, v) if (p == NULL) ht[hash_v] = en else p->n= en else en->v = v End.
สำหรับการลบ:
Begin Declare Function Remove(int k) int hash_v = HashFunc(k) HashTableEntry* en = ht[hash_v] HashTableEntry* p= NULL if (en == NULL or en->k != k) Print “No Element found at key” return while (en->n != NULL) p = en en = en->n if (p != NULL) p->n = en->n delete en Print “Element Deleted” End.
สำหรับค้นหาค่าคีย์:
Begin Declare function SearchKey(int k) int hash_v = HashFunc(k) bool flag = false HashTableEntry* en = ht[hash_v] if (en != NULL) while (en != NULL) if (en->k == k) flag = true if (flag) Print “Element found at key” Print en->v en = en->n if (!flag) Print “No Element found at key” End.
โค้ดตัวอย่าง
#include <iostream> const int T_S = 200; using namespace std; struct HashTableEntry { int v, k; HashTableEntry *n; HashTableEntry *p; HashTableEntry(int k, int v) { this->k = k; this->v = v; this->n = NULL; } }; class HashMapTable { public: HashTableEntry **ht, **top; HashMapTable() { ht = new HashTableEntry*[T_S]; for (int i = 0; i < T_S; i++) ht[i] = NULL; } int HashFunc(int key) { return key % T_S; } void Insert(int k, int v) { int hash_v = HashFunc(k); HashTableEntry* p = NULL; HashTableEntry* en = ht[hash_v]; while (en!= NULL) { p = en; en = en->n; } if (en == NULL) { en = new HashTableEntry(k, v); if (p == NULL) { ht[hash_v] = en; } else { p->n = en; } } else { en->v = v; } } void Remove(int k) { int hash_v = HashFunc(k); HashTableEntry* en = ht[hash_v]; HashTableEntry* p = NULL; if (en == NULL || en->k != k) { cout<<"No Element found at key "<<k<<endl; return; } while (en->n != NULL) { p = en; en = en->n; } if (p != NULL) { p->n = en->n; } delete en; cout<<"Element Deleted"<<endl; } void SearchKey(int k) { int hash_v = HashFunc(k); bool flag = false; HashTableEntry* en = ht[hash_v]; if (en != NULL) { while (en != NULL) { if (en->k == k) { flag = true; } if (flag) { cout<<"Element found at key "<<k<<": "; cout<<en->v<<endl; } en = en->n; } } if (!flag) cout<<"No Element found at key "<<k<<endl; } ~HashMapTable() { delete [] ht; } }; int main() { HashMapTable hash; int k, v; int c; while (1) { cout<<"1.Insert element into the table"<<endl; cout<<"2.Search element from the key"<<endl; cout<<"3.Delete element at a key"<<endl; cout<<"4.Exit"<<endl; cout<<"Enter your choice: "; cin>>c; switch(c) { case 1: cout<<"Enter element to be inserted: "; cin>>v; cout<<"Enter key at which element to be inserted: "; cin>>k; hash.Insert(k, v); break; case 2: cout<<"Enter key of the element to be searched: "; cin>>k; hash.SearchKey(k); break; case 3: cout<<"Enter key of the element to be deleted: "; cin>>k; hash.Remove(k); break; case 4: exit(1); default: cout<<"\nEnter correct option\n"; } } return 0; }
ผลลัพธ์
1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 1 Enter element to be inserted: 2 Enter key at which element to be inserted: 1 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 1 Enter element to be inserted: 3 Enter key at which element to be inserted: 4 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 1 Enter element to be inserted: 7 Enter key at which element to be inserted: 6 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 1 Enter element to be inserted: 8 Enter key at which element to be inserted: 9 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 2 Enter key of the element to be searched: 6 Element found at key 6: 7 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 2 Enter key of the element to be searched: 7 No Element found at key 7 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 3 Enter key of the element to be deleted: 9 Element Deleted 1.Insert element into the table 2.Search element from the key 3.Delete element at a key 4.Exit Enter your choice: 4