In this post, we will look into deletion operation in an Array, i.e., how to delete an element from an Array, such as:
Deleting Elements from an Array when it is Unsorted
Deleting Elements from an Array when it is Sorted
Deleting Elements in an Array when it is Unsorted
In the delete operation, the element to be deleted is searched using the linear search, and then the delete operation is performed followed by shifting the elements.
C++
// C++ program to implement delete operation in a
// unsorted array
#include <iostream>
usingnamespacestd;
// To search a key to be deleted
intfindElement(intarr[], intn, intkey);
// Function to delete an element
intdeleteElement(intarr[], intn, intkey)
{
// Find position of element to be deleted
intpos = findElement(arr, n, key);
if(pos == -1) {
cout << "Element not found";
returnn;
}
// Deleting element
inti;
for(i = pos; i < n - 1; i++)
arr[i] = arr[i + 1];
returnn - 1;
}
// Function to implement search operation
intfindElement(intarr[], intn, intkey)
{
inti;
for(i = 0; i < n; i++)
if(arr[i] == key)
returni;
return-1;
}
// Driver's code
intmain()
{
inti;
intarr[] = { 10, 50, 30, 40, 20 };
intn = sizeof(arr) / sizeof(arr[0]);
intkey = 30;
cout << "Array before deletion\n";
for(i = 0; i < n; i++)
cout << arr[i] << " ";
// Function call
n = deleteElement(arr, n, key);
cout << "\n\nArray after deletion\n";
for(i = 0; i < n; i++)
cout << arr[i] << " ";
return0;
}
// This code is contributed by shubhamsingh10
C
// C program to implement delete operation in a
// unsorted array
#include <stdio.h>
// To search a key to be deleted
intfindElement(intarr[], intn, intkey);
// Function to delete an element
intdeleteElement(intarr[], intn, intkey)
{
// Find position of element to be deleted
intpos = findElement(arr, n, key);
if(pos == -1) {
printf("Element not found");
returnn;
}
// Deleting element
inti;
for(i = pos; i < n - 1; i++)
arr[i] = arr[i + 1];
returnn - 1;
}
// Function to implement search operation
intfindElement(intarr[], intn, intkey)
{
inti;
for(i = 0; i < n; i++)
if(arr[i] == key)
returni;
return-1;
}
// Driver's code
intmain()
{
inti;
intarr[] = { 10, 50, 30, 40, 20 };
intn = sizeof(arr) / sizeof(arr[0]);
intkey = 30;
printf("Array before deletion\n");
for(i = 0; i < n; i++)
printf("%d ", arr[i]);
// Function call
n = deleteElement(arr, n, key);
printf("\nArray after deletion\n");
for(i = 0; i < n; i++)
printf("%d ", arr[i]);
return0;
}
Java
// Java program to implement delete
// operation in an unsorted array
classMain {
// function to search a key to
// be deleted
staticintfindElement(intarr[], intn, intkey)
{
inti;
for(i = 0; i < n; i++)
if(arr[i] == key)
returni;
return-1;
}
// Function to delete an element
staticintdeleteElement(intarr[], intn, intkey)
{
// Find position of element to be
// deleted
intpos = findElement(arr, n, key);
if(pos == -1) {
System.out.println("Element not found");
returnn;
}
// Deleting element
inti;
for(i = pos; i < n - 1; i++)
arr[i] = arr[i + 1];
returnn - 1;
}
// Driver's Code
publicstaticvoidmain(String args[])
{
inti;
intarr[] = { 10, 50, 30, 40, 20};
intn = arr.length;
intkey = 30;
System.out.println("Array before deletion");
for(i = 0; i < n; i++)
System.out.print(arr[i] + " ");
// Function call
n = deleteElement(arr, n, key);
System.out.println("\n\nArray after deletion");
for(i = 0; i < n; i++)
System.out.print(arr[i] + " ");
}
}
Python3
# Python program to delete an element
# from an unsorted array
# Driver's code
if__name__ =='__main__':
# Declaring array and key to delete
arr =[10, 50, 30, 40, 20]
key =30
print("Array before deletion:")
print(arr)
# deletes key if found in the array
# otherwise shows error not in list
arr.remove(key)
print("Array after deletion")
print(arr)
# This code is contributed by Aditi Sharma.
C#
// C# program to implement delete
// operation in an unsorted array
usingSystem;
classmain {
// Function to search a
// key to be deleted
staticintfindElement(int[] arr, intn, intkey)
{
inti;
for(i = 0; i < n; i++)
if(arr[i] == key)
returni;
return-1;
}
// Function to delete an element
staticintdeleteElement(int[] arr, intn, intkey)
{
// Find position of element
// to be deleted
intpos = findElement(arr, n, key);
if(pos == -1) {
Console.WriteLine("Element not found");
returnn;
}
// Deleting element
inti;
for(i = pos; i < n - 1; i++)
arr[i] = arr[i + 1];
returnn - 1;
}
// Driver Code
publicstaticvoidMain()
{
inti;
int[] arr = { 10, 50, 30, 40, 20 };
intn = arr.Length;
intkey = 30;
Console.Write("Array before deletion ");
for(i = 0; i < n; i++)
Console.Write(arr[i] + " ");
Console.WriteLine();
// Function call
n = deleteElement(arr, n, key);
Console.Write("Array after deletion ");
for(i = 0; i < n; i++)
Console.Write(arr[i] + " ");
}
}
// This code is contributed by vt_m.
Javascript
// Java script program to implement delete
// operation in an unsorted array
// function to search a key to
// be deleted
functionfindElement(arr,n,key)
{
let i;
for(i = 0; i < n; i++)
if(arr[i] == key)
returni;
return-1;
}
// Function to delete an element
functiondeleteElement(arr,n,key)
{
// Find position of element to be
// deleted
let pos = findElement(arr, n, key);
if(pos == -1)
{
document.write("Element not found");
returnn;
}
// Deleting element
let i;
for(i = pos; i< n - 1; i++)
arr[i] = arr[i + 1];
returnn - 1;
}
// Driver Code
let i;
let arr = [10, 50, 30, 40, 20];
let n = arr.length;
let key = 30;
document.write("Array before deletion<br>");
for(i=0; i<n; i++)
document.write(arr[i] + " ");
n = deleteElement(arr, n, key);
document.write("<br><br>Array after deletion<br>");
for(i=0; i<n; i++)
document.write(arr[i]+" ");
// This code is contributed by sravan kumar Gottumukkala
PHP
<?php
// PHP program to implement delete
// operation in an unsorted array
// To search a key to be deleted
functionfindElement(&$arr, $n, $key)
{
for($i= 0; $i< $n; $i++)
if($arr[$i] == $key)
return$i;
return-1;
}
// Function to delete an element
functiondeleteElement(&$arr, $n, $key)
{
// Find position of element to
// be deleted
$pos= findElement($arr, $n, $key);
if($pos== -1)
{
echo"Element not found";
return$n;
}
// Deleting element
for($i= $pos; $i< $n- 1; $i++)
$arr[$i] = $arr[$i+ 1];
return$n- 1;
}
// Driver code
$arr= array(10, 50, 30, 40, 20);
$n= count($arr);
$key= 30;
echo"Array before deletion\n";
for($i= 0; $i< $n; $i++)
echo$arr[$i] . " ";
// Function call
$n= deleteElement($arr, $n, $key);
echo"\nArray after deletion\n";
for($i= 0; $i< $n; $i++)
echo$arr[$i] . " ";
// This code is contributed by
// Rajput-Ji
?>
Output
Array before deletion
10 50 30 40 20
Array after deletion
10 50 40 20
Time Complexity: O(N) Auxiliary Space: O(1)
Deleting Elements in an Array when it is Sorted
In the delete operation, the element to be deleted is searched using binary search, and then the delete operation is performed followed by shifting the elements.
Performing delete operation
Below is the implementation of the above approach:
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