Merge pull request #531 from harshnamdev98/master

Hashing with chaining in c++

Author: probot-auto-merge[bot]

Hash_alg/Hashing_chaining.cpp

@@ -0,0 +1,89 @@
+// CPP program to implement hashing with chaining 
+#include<iostream> 
+#include <list> 
+using namespace std; 
+
+class Hash 
+{ 
+	int BUCKET; // No. of buckets 
+
+	// Pointer to an array containing buckets 
+	list<int> *table; 
+public: 
+	Hash(int V); // Constructor 
+
+	// inserts a key into hash table 
+	void insertItem(int x); 
+
+	// deletes a key from hash table 
+	void deleteItem(int key); 
+
+	// hash function to map values to key 
+	int hashFunction(int x) { 
+		return (x % BUCKET); 
+	} 
+
+	void displayHash(); 
+}; 
+
+Hash::Hash(int b) 
+{ 
+	this->BUCKET = b; 
+	table = new list<int>[BUCKET]; 
+} 
+
+void Hash::insertItem(int key) 
+{ 
+	int index = hashFunction(key); 
+	table[index].push_back(key); 
+} 
+
+void Hash::deleteItem(int key) 
+{ 
+// get the hash index of key 
+int index = hashFunction(key); 
+
+// find the key in (inex)th list 
+list <int> :: iterator i; 
+for (i = table[index].begin(); 
+		i != table[index].end(); i++) { 
+	if (*i == key) 
+	break; 
+} 
+
+// if key is found in hash table, remove it 
+if (i != table[index].end()) 
+	table[index].erase(i); 
+} 
+
+// function to display hash table 
+void Hash::displayHash() { 
+for (int i = 0; i < BUCKET; i++) { 
+	cout << i; 
+	for (auto x : table[i]) 
+	cout << " --> " << x; 
+	cout << endl; 
+} 
+} 
+
+// Driver program 
+int main() 
+{ 
+// array that contains keys to be mapped 
+int a[] = {15, 11, 27, 8, 12}; 
+int n = sizeof(a)/sizeof(a[0]); 
+
+// insert the keys into the hash table 
+Hash h(7); // 7 is count of buckets in 
+			// hash table 
+for (int i = 0; i < n; i++) 
+	h.insertItem(a[i]); 
+
+// delete 12 from hash table 
+h.deleteItem(12); 
+
+// display the Hash table 
+h.displayHash(); 
+
+return 0; 
+} 

Hash_alg/Hashing_with_chaining.cpp

@@ -0,0 +1,89 @@
+// CPP program to implement hashing with chaining 
+#include<iostream> 
+#include <list> 
+using namespace std; 
+
+class Hash 
+{ 
+	int BUCKET; // No. of buckets 
+
+	// Pointer to an array containing buckets 
+	list<int> *table; 
+public: 
+	Hash(int V); // Constructor 
+
+	// inserts a key into hash table 
+	void insertItem(int x); 
+
+	// deletes a key from hash table 
+	void deleteItem(int key); 
+
+	// hash function to map values to key 
+	int hashFunction(int x) { 
+		return (x % BUCKET); 
+	} 
+
+	void displayHash(); 
+}; 
+
+Hash::Hash(int b) 
+{ 
+	this->BUCKET = b; 
+	table = new list<int>[BUCKET]; 
+} 
+
+void Hash::insertItem(int key) 
+{ 
+	int index = hashFunction(key); 
+	table[index].push_back(key); 
+} 
+
+void Hash::deleteItem(int key) 
+{ 
+// get the hash index of key 
+int index = hashFunction(key); 
+
+// find the key in (inex)th list 
+list <int> :: iterator i; 
+for (i = table[index].begin(); 
+		i != table[index].end(); i++) { 
+	if (*i == key) 
+	break; 
+} 
+
+// if key is found in hash table, remove it 
+if (i != table[index].end()) 
+	table[index].erase(i); 
+} 
+
+// function to display hash table 
+void Hash::displayHash() { 
+for (int i = 0; i < BUCKET; i++) { 
+	cout << i; 
+	for (auto x : table[i]) 
+	cout << " --> " << x; 
+	cout << endl; 
+} 
+} 
+
+// Driver program 
+int main() 
+{ 
+// array that contains keys to be mapped 
+int a[] = {15, 11, 27, 8, 12}; 
+int n = sizeof(a)/sizeof(a[0]); 
+
+// insert the keys into the hash table 
+Hash h(7); // 7 is count of buckets in 
+			// hash table 
+for (int i = 0; i < n; i++) 
+	h.insertItem(a[i]); 
+
+// delete 12 from hash table 
+h.deleteItem(12); 
+
+// display the Hash table 
+h.displayHash(); 
+
+return 0; 
+}