# Common operations on various Data Structures

• Difficulty Level : Medium
• Last Updated : 07 Aug, 2022

Data Structure is the way of storing data in computer’s memory so that it can be used easily and efficiently. There are different data-structures used for the storage of data. It can also be define as a mathematical or logical model of a particular organization of data items. The representation of particular data structure in the main memory of a computer is called as storage structure. For Examples: Array, Stack, Queue, Tree, Graph, etc.

Operations on different Data Structure:
There are different types of operations that can be performed for the manipulation of data in every data structure. Some operations are explained and illustrated below:

• Traversing: Traversing a Data Structure means to visit the element stored in it. It visits data in a systematic manner.This can be done with any type of DS.
Below is the program to illustrate traversal in an array:

## Array

 `// C++ program to traversal in an array``#include ``using` `namespace` `std;` `// Driver Code``int` `main()``{``    ``// Initialise array``    ``int` `arr[] = { 1, 2, 3, 4 };` `    ``// size of array``    ``int` `N = ``sizeof``(arr) / ``sizeof``(arr);` `    ``// Traverse the element of arr[]``    ``for` `(``int` `i = 0; i < N; i++) {` `        ``// Print the element``        ``cout << arr[i] << ``' '``;``    ``}` `    ``return` `0;``}`

## Stack

 `// C++ program to traversal in an stack``#include ``using` `namespace` `std;` `// Function to print the element in stack``void` `printStack(stack<``int``>& St)``{` `    ``// Traverse the stack``    ``while` `(!St.empty()) {` `        ``// Print top element``        ``cout << St.top() << ``' '``;` `        ``// Pop top element``        ``St.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``// Initialise stack``    ``stack<``int``> St;` `    ``// Insert Element in stack``    ``St.push(4);``    ``St.push(3);``    ``St.push(2);``    ``St.push(1);` `    ``// Print elements in stack``    ``printStack(St);``    ``return` `0;``}`

## Queue

 `// C++ program to traversal``// in an queue``#include ``using` `namespace` `std;` `// Function to print the``// element in queue``void` `printQueue(queue<``int``>& Q)``{``    ``// Traverse the stack``    ``while` `(!Q.empty()) {` `        ``// Print top element``        ``cout << Q.front() << ``' '``;` `        ``// Pop top element``        ``Q.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``// Initialise queue``    ``queue<``int``> Q;` `    ``// Insert element``    ``Q.push(1);``    ``Q.push(2);``    ``Q.push(3);``    ``Q.push(4);` `    ``// Print elements``    ``printQueue(Q);``    ``return` `0;``}`

 `// C++ program to traverse the``// given linked list``#include ``using` `namespace` `std;``struct` `Node {``    ``int` `data;``    ``Node* next;``};` `// Function that allocates a new``// node with given data``Node* newNode(``int` `data)``{``    ``Node* new_node = ``new` `Node;``    ``new_node->data = data;``    ``new_node->next = NULL;``    ``return` `new_node;``}` `// Function to insert a new node``// at the end of linked list``Node* insertEnd(Node* head, ``int` `data)``{``    ``// If linked list is empty,``    ``// Create a new node``    ``if` `(head == NULL)``        ``return` `newNode(data);` `    ``// If we have not reached the end``    ``// Keep traversing recursively``    ``else``        ``head->next = insertEnd(head->next, data);``    ``return` `head;``}` `/// Function to traverse given LL``void` `traverse(Node* head)``{``    ``if` `(head == NULL)``        ``return``;` `    ``// If head is not NULL,``    ``// print current node and``    ``// recur for remaining list``    ``cout << head->data << ``" "``;` `    ``traverse(head->next);``}` `// Driver Code``int` `main()``{``    ``// Given Linked List``    ``Node* head = NULL;``    ``head = insertEnd(head, 1);``    ``head = insertEnd(head, 2);``    ``head = insertEnd(head, 3);``    ``head = insertEnd(head, 4);` `    ``// Function Call to traverse LL``    ``traverse(head);``}`

Output:

`1 2 3 4`

Below is the program to illustrate traversal in an array in java:

## C++

 `// C++ program to traversal in an array``#include ``using` `namespace` `std;` `// Driver Code``int` `main()``{``    ``// Initialise array``    ``int` `arr[] = { 1, 2, 3, 4 };` `    ``// size of array``    ``int` `N = ``sizeof``(arr)/``sizeof``(arr);` `    ``// Traverse the element of arr[]``    ``for` `(``int` `i = 0; i < N; i++) {` `        ``// Print the element``        ``cout << arr[i] << ``" "``;``    ``}``    ``return` `0;``}` `// This code is contributed by jana_sayantan.`

## Java

 `// Java program to traversal in an array` `import` `java.util.*;` `class` `GFG{` `// Driver Code``public` `static` `void` `main(String[] args)``{``    ``// Initialise array``    ``int` `arr[] = { ``1``, ``2``, ``3``, ``4` `};` `    ``// size of array``    ``int` `N = arr.length;` `    ``// Traverse the element of arr[]``    ``for` `(``int` `i = ``0``; i < N; i++) {` `        ``// Print the element``        ``System.out.print(arr[i] + ``" "``);``    ``}` `}``}` `// This code contributed by Rajput-Ji`

## Python3

 `# Python program to traversal in an array` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:``  ` `    ``# Initialise array``    ``arr ``=` `[ ``1``, ``2``, ``3``, ``4` `];` `    ``# size of array``    ``N ``=` `len``(arr);` `    ``# Traverse the element of arr``    ``for` `i ``in` `range``(N):` `        ``# Print element``        ``print``(arr[i], end``=``" "``);``    ` `# This code is contributed by Rajput-Ji`

## C#

 `// C# program to traversal in an array` `using` `System;` `public` `class` `GFG {` `    ``// Driver Code``    ``public` `static` `void` `Main(String[] args) {``        ``// Initialise array``        ``int` `[]arr = { 1, 2, 3, 4 };` `        ``// size of array``        ``int` `N = arr.Length;` `        ``// Traverse the element of []arr``        ``for` `(``int` `i = 0; i < N; i++) {` `            ``// Print the element``            ``Console.Write(arr[i] + ``" "``);``        ``}` `    ``}``}`   `// This code contributed by Rajput-Ji`

## Javascript

 ``

Below is the program to illustrate traversal in a Stack in java:

## Java

 `// Java program to traversal in an stack` `import` `java.util.*;` `class` `GFG{` `// Function to print the element in stack``static` `void` `printStack(Stack St)``{` `    ``// Traverse the stack``    ``while` `(!St.isEmpty()) {` `        ``// Print top element``        ``System.out.print(St.peek() +``" "``);` `        ``// Pop top element``        ``St.pop();``    ``}``}` `// Driver Code``public` `static` `void` `main(String[] args)``{``    ``// Initialise stack``    ``Stack St = ``new` `Stack<>() ;` `    ``// Insert Element in stack``    ``St.add(``4``);``    ``St.add(``3``);``    ``St.add(``2``);``    ``St.add(``1``);` `    ``// Print elements in stack``    ``printStack(St);``}``}` `// This code contributed by Rajput-Ji`

## C#

 `// C# program to traversal in an stack``using` `System;``using` `System.Collections.Generic;` `public` `class` `GFG {` `  ``// Function to print the element in stack``  ``static` `void` `printStack(Stack<``int``> St) {` `    ``// Traverse the stack``    ``while` `(St.Count != 0) {` `      ``// Print top element``      ``Console.Write(St.Peek() + ``" "``);` `      ``// Pop top element``      ``St.Pop();``    ``}``  ``}` `  ``// Driver Code``  ``public` `static` `void` `Main(String[] args)``  ``{` `    ``// Initialise stack``    ``Stack<``int``> St = ``new` `Stack<``int``>();` `    ``// Insert Element in stack``    ``St.Push(4);``    ``St.Push(3);``    ``St.Push(2);``    ``St.Push(1);` `    ``// Print elements in stack``    ``printStack(St);``  ``}``}` `// This code is contributed by Rajput-Ji`

## Javascript

 ``

• Searching: Searching means to find a particular element in the given data-structure. It is considered as successful when the required element is found. Searching is the operation which we can performed on data-structures like array, linked-list, tree, graph, etc.
Below is the program to illustrate searching an element in an array:

## Array

 `// C++ program to searching in an array``#include ``using` `namespace` `std;` `// Function that finds element K in the``// array``void` `findElement(``int` `arr[], ``int` `N, ``int` `K)``{` `    ``// Traverse the element of arr[]``    ``// to find element K``    ``for` `(``int` `i = 0; i < N; i++) {` `        ``// If Element is present then``        ``// print the index and return``        ``if` `(arr[i] == K) {``            ``cout << ``"Element found!"``;``            ``return``;``        ``}``    ``}` `    ``cout << ``"Element Not found!"``;``}` `// Driver Code``int` `main()``{``    ``// Initialise array``    ``int` `arr[] = { 1, 2, 3, 4 };` `    ``// Element to be found``    ``int` `K = 3;` `    ``// size of array``    ``int` `N = ``sizeof``(arr) / ``sizeof``(arr);` `    ``// Function Call``    ``findElement(arr, N, K);``    ``return` `0;``}`

## Stack

 `// C++ program to find element in stack``#include ``using` `namespace` `std;` `// Function to find element in stack``void` `findElement(stack<``int``>& St, ``int` `K)``{` `    ``// Traverse the stack``    ``while` `(!St.empty()) {` `        ``// Check if top is K``        ``if` `(St.top() == K) {``            ``cout << ``"Element found!"``;``            ``return``;``        ``}` `        ``// Pop top element``        ``St.pop();``    ``}` `    ``cout << ``"Element Not found!"``;``}` `// Driver Code``int` `main()``{``    ``// Initialise stack``    ``stack<``int``> St;` `    ``// Insert Element in stack``    ``St.push(4);``    ``St.push(3);``    ``St.push(2);``    ``St.push(1);` `    ``// Element to be found``    ``int` `K = 3;` `    ``// Function Call``    ``findElement(St, K);``    ``return` `0;``}`

## Queue

 `// C++ program to find given element``// in an queue``#include ``using` `namespace` `std;` `// Function to find element in queue``void` `findElement(queue<``int``>& Q, ``int` `K)``{` `    ``// Traverse the stack``    ``while` `(!Q.empty()) {` `        ``// Check if top is K``        ``if` `(Q.front() == K) {``            ``cout << ``"Element found!"``;``            ``return``;``        ``}` `        ``// Pop top element``        ``Q.pop();``    ``}` `    ``cout << ``"Element Not found!"``;``}` `// Driver Code``int` `main()``{``    ``// Initialise queue``    ``queue<``int``> Q;` `    ``// Insert element``    ``Q.push(1);``    ``Q.push(2);``    ``Q.push(3);``    ``Q.push(4);` `    ``// Element to be found``    ``int` `K = 3;` `    ``// Print elements``    ``findElement(Q, K);``    ``return` `0;``}`

 `// C++ program to traverse the``// given linked list``#include ``using` `namespace` `std;``struct` `Node {``    ``int` `data;``    ``Node* next;``};` `// Function that allocates a new``// node with given data``Node* newNode(``int` `data)``{``    ``Node* new_node = ``new` `Node;``    ``new_node->data = data;``    ``new_node->next = NULL;``    ``return` `new_node;``}` `// Function to insert a new node``// at the end of linked list``Node* insertEnd(Node* head, ``int` `data)``{``    ``// If linked list is empty,``    ``// Create a new node``    ``if` `(head == NULL)``        ``return` `newNode(data);` `    ``// If we have not reached the end``    ``// Keep traversing recursively``    ``else``        ``head->next = insertEnd(head->next, data);``    ``return` `head;``}` `/// Function to traverse given LL``bool` `traverse(Node* head, ``int` `K)``{``    ``if` `(head == NULL)``        ``return` `false``;` `    ``// If node with value K is found``    ``// return true``    ``if` `(head->data == K)``        ``return` `true``;` `    ``return` `traverse(head->next, K);``}` `// Driver Code``int` `main()``{``    ``// Given Linked List``    ``Node* head = NULL;``    ``head = insertEnd(head, 1);``    ``head = insertEnd(head, 2);``    ``head = insertEnd(head, 3);``    ``head = insertEnd(head, 4);` `    ``// Element to be found``    ``int` `K = 3;` `    ``// Function Call to traverse LL``    ``if` `(traverse(head, K)) {``        ``cout << ``"Element found!"``;``    ``}``    ``else` `{``        ``cout << ``"Element Not found!"``;``    ``}``}`

Output:

`Element found!`

• Insertion: It is the operation which we apply on all the data-structures. Insertion means to add an element in the given data structure. The operation of insertion is successful when the required element is added to the required data-structure. It is unsuccessful in some cases when the size of the data structure is full and when there is no space in the data-structure to add any additional element. The insertion has the same name as an insertion in the data-structure as an array, linked-list, graph, tree. In stack, this operation is called Push. In the queue, this operation is called Enqueue.
Below is the program to illustrate insertion in stack:

## Array

 `// C++ program for insertion in array``#include ``using` `namespace` `std;` `// Function to print the array element``void` `printArray(``int` `arr[], ``int` `N)``{``    ``// Traverse the element of arr[]``    ``for` `(``int` `i = 0; i < N; i++) {` `        ``// Print the element``        ``cout << arr[i] << ``' '``;``    ``}``}` `// Driver Code``int` `main()``{``    ``// Initialise array``    ``int` `arr;` `    ``// size of array``    ``int` `N = 4;` `    ``// Insert elements in array``    ``for` `(``int` `i = 1; i < 5; i++) {``        ``arr[i - 1] = i;``    ``}` `    ``// Print array element``    ``printArray(arr, N);``    ``return` `0;``}`

## Stack

 `// C++ program for insertion in array``#include ``using` `namespace` `std;` `// Function to print the element in stack``void` `printStack(stack<``int``>& St)``{` `    ``// Traverse the stack``    ``while` `(!St.empty()) {` `        ``// Print top element``        ``cout << St.top() << ``' '``;` `        ``// Pop top element``        ``St.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``// Initialise stack``    ``stack<``int``> St;` `    ``// Insert Element in stack``    ``St.push(4);``    ``St.push(3);``    ``St.push(2);``    ``St.push(1);` `    ``// Print elements in stack``    ``printStack(St);``    ``return` `0;``}`

## Queue

 `// C++ program for insertion in queue``#include ``using` `namespace` `std;` `// Function to print the``// element in queue``void` `printQueue(queue<``int``>& Q)``{``    ``// Traverse the stack``    ``while` `(!Q.empty()) {` `        ``// Print top element``        ``cout << Q.front() << ``' '``;` `        ``// Pop top element``        ``Q.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``// Initialise queue``    ``queue<``int``> Q;` `    ``// Insert element``    ``Q.push(1);``    ``Q.push(2);``    ``Q.push(3);``    ``Q.push(4);` `    ``// Print elements``    ``printQueue(Q);``    ``return` `0;``}`

 `// C++ program for insertion in LL``#include ``using` `namespace` `std;``struct` `Node {``    ``int` `data;``    ``Node* next;``};` `// Function that allocates a new``// node with given data``Node* newNode(``int` `data)``{``    ``Node* new_node = ``new` `Node;``    ``new_node->data = data;``    ``new_node->next = NULL;``    ``return` `new_node;``}` `// Function to insert a new node``// at the end of linked list``Node* insertEnd(Node* head, ``int` `data)``{``    ``// If linked list is empty,``    ``// Create a new node``    ``if` `(head == NULL)``        ``return` `newNode(data);` `    ``// If we have not reached the end``    ``// Keep traversing recursively``    ``else``        ``head->next = insertEnd(head->next, data);``    ``return` `head;``}` `/// Function to traverse given LL``void` `traverse(Node* head)``{``    ``if` `(head == NULL)``        ``return``;` `    ``// If head is not NULL,``    ``// print current node and``    ``// recur for remaining list``    ``cout << head->data << ``" "``;` `    ``traverse(head->next);``}` `// Driver Code``int` `main()``{``    ``// Given Linked List``    ``Node* head = NULL;``    ``head = insertEnd(head, 1);``    ``head = insertEnd(head, 2);``    ``head = insertEnd(head, 3);``    ``head = insertEnd(head, 4);` `    ``// Function Call to traverse LL``    ``traverse(head);``}`

Output:

`1 2 3 4`

• Deletion: It is the operation which we apply on all the data-structures. Deletion means to delete an element in the given data structure. The operation of deletion is successful when the required element is deleted from the data structure. The deletion has the same name as a deletion in the data-structure as an array, linked-list, graph, tree, etc. In stack, this operation is called Pop. In Queue this operation is called Dequeue.
Below is the program to illustrate dequeue in Queue:

## Stack

 `// C++ program for insertion in array``#include ``using` `namespace` `std;` `// Function to print the element in stack``void` `printStack(stack<``int``> St)``{``    ``// Traverse the stack``    ``while` `(!St.empty()) {` `        ``// Print top element``        ``cout << St.top() << ``' '``;` `        ``// Pop top element``        ``St.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``// Initialise stack``    ``stack<``int``> St;` `    ``// Insert Element in stack``    ``St.push(4);``    ``St.push(3);``    ``St.push(2);``    ``St.push(1);` `    ``// Print elements before pop``    ``// operation on stack``    ``printStack(St);` `    ``cout << endl;` `    ``// Pop the top element``    ``St.pop();` `    ``// Print elements after pop``    ``// operation on stack``    ``printStack(St);``    ``return` `0;``}`

## Queue

 `// C++ program to illustrate dequeue``// in queue``#include ``using` `namespace` `std;` `// Function to print the element``// of the queue``void` `printQueue(queue<``int``> myqueue)``{``    ``// Traverse the queue and print``    ``// element at the front of queue``    ``while` `(!myqueue.empty()) {` `        ``// Print the first element``        ``cout << myqueue.front() << ``' '``;` `        ``// Dequeue the element from the``        ``// front of the queue``        ``myqueue.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``// Declare a queue``    ``queue<``int``> myqueue;` `    ``// Insert element in queue from``    ``// 0 to 5``    ``for` `(``int` `i = 1; i < 5; i++) {` `        ``// Insert element at the``        ``// front of the queue``        ``myqueue.push(i);``    ``}` `    ``// Print element beforepop``    ``// from queue``    ``printQueue(myqueue);` `    ``cout << endl;` `    ``// Pop the front element``    ``myqueue.pop();` `    ``// Print element after pop``    ``// from queue``    ``printQueue(myqueue);``    ``return` `0;``}`

 `// C++ program for insertion in LL``#include ``using` `namespace` `std;``struct` `Node {``    ``int` `data;``    ``Node* next;``};` `// Function that allocates a new``// node with given data``Node* newNode(``int` `data)``{``    ``Node* new_node = ``new` `Node;``    ``new_node->data = data;``    ``new_node->next = NULL;``    ``return` `new_node;``}` `// Function to insert a new node``// at the end of linked list``Node* insertEnd(Node* head, ``int` `data)``{``    ``// If linked list is empty,``    ``// Create a new node``    ``if` `(head == NULL)``        ``return` `newNode(data);` `    ``// If we have not reached the end``    ``// Keep traversing recursively``    ``else``        ``head->next = insertEnd(head->next, data);``    ``return` `head;``}` `/// Function to traverse given LL``void` `traverse(Node* head)``{``    ``if` `(head == NULL)``        ``return``;` `    ``// If head is not NULL,``    ``// print current node and``    ``// recur for remaining list``    ``cout << head->data << ``" "``;` `    ``traverse(head->next);``}` `// Driver Code``int` `main()``{``    ``// Given Linked List``    ``Node* head = NULL;``    ``head = insertEnd(head, 1);``    ``head = insertEnd(head, 2);``    ``head = insertEnd(head, 3);``    ``head = insertEnd(head, 4);` `    ``// Print before deleting the first``    ``// element from LL``    ``traverse(head);` `    ``// Move head pointer to forward``    ``// to remove the first element` `    ``// If LL has more than 1 element``    ``if` `(head->next != NULL) {``        ``head = head->next;``    ``}``    ``else` `{``        ``head = NULL;``    ``}` `    ``cout << endl;` `    ``// Print after deleting the first``    ``// element from LL``    ``traverse(head);``}`

Output:

```1 2 3 4
2 3 4```

Some other method :

Create: –
It reverses memory for program elements by declaring them. The creation of data structure
Can be done during

1. Compile-time
2. Run-time.

You can use malloc() function.
Selection:-
It selects specific data from present data. You can any select specific data by giving condition in loop .
Update
It updates the data in the data structure. You can also update any specific data by giving some condition in loop like select approach.
Sort
Sorting data in a particular order (ascending or descending).
We can take the help of many sorting algorithms to sort data in less time. Example: bubble sort which takes O(n^2)time to sort data. There are many algorithms present like merge sort, insertion sort, selection sort, quick sort, etc.
Merge
Merging data of two different orders in a specific order may ascend or descend. We use merge sort to merge sort data.

Split Data
Dividing data into different sub-parts to make the process complete in less time.

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