Given an array arr[], the task is to replace every element of the array with the sum of elements on its right side.
Examples:
Input: arr[] = {1, 2, 5, 2, 2, 5}
Output: 16 14 9 7 5 0
Input: arr[] = {5, 1, 3, 2, 4}
Output: 10 9 6 4 0
Naive Approach: A simple approach is to run two loops, Outer loop to fix each element one by one and inner loop to calculate sum of elements on right side of fixed element.
// THIS CODE IS CONTRIBUTED BY KIRTI AGARWAL(KIRTIAGARWAL23121999) // C++ program to Replace every element of array // with sum of elements on its right side #include<bits/stdc++.h> using namespace std;
// Function to replace every element // of the array to the sum of elements // on the right side of the array void replaceElement( int arr[], int n){
for ( int i = 0; i<n; i++){
int sum = 0;
for ( int j = i+1; j<n; j++){
sum += arr[j];
}
arr[i] = sum;
}
for ( int i = 0; i<n; i++){
cout<<arr[i]<< " " ;
}
} // Driver code to test above function int main(){
int arr[] = { 1, 2, 5, 2, 2, 5 };
int n = sizeof (arr) / sizeof (arr[0]);
replaceElement(arr, n);
} |
public class GFG {
public static void main(String[] args)
{
int [] arr = { 1 , 2 , 5 , 2 , 2 , 5 };
int n = arr.length;
replaceElement(arr, n);
}
/**
* Function to replace every element of the array to the
* sum of elements on the right side of the array
* @param arr the input array of integers
* @param n the size of the array
*/
public static void replaceElement( int [] arr, int n)
{
for ( int i = 0 ; i < n; i++) {
int sum = 0 ;
for ( int j = i + 1 ; j < n; j++) {
sum += arr[j];
}
arr[i] = sum;
}
for ( int i = 0 ; i < n; i++) {
System.out.print(arr[i] + " " );
}
}
} |
# Function to replace every element # of the array to the sum of elements # on the right side of the array def replaceElement(arr, n):
for i in range (n):
sum = 0
for j in range (i + 1 , n):
sum + = arr[j]
arr[i] = sum
for i in range (n):
print (arr[i], end = " " )
# Driver code to test above function arr = [ 1 , 2 , 5 , 2 , 2 , 5 ]
n = len (arr)
replaceElement(arr, n) |
using System;
namespace GFG {
class Program {
static void Main( string [] args)
{
int [] arr = { 1, 2, 5, 2, 2, 5 };
int n = arr.Length;
ReplaceElement(arr, n);
}
/**
* Function to replace every element of the array to the
* sum of elements on the right side of the array
* @param arr the input array of integers
* @param n the size of the array
*/
static void ReplaceElement( int [] arr, int n)
{
for ( int i = 0; i < n; i++) {
int sum = 0;
for ( int j = i + 1; j < n; j++) {
sum += arr[j];
}
arr[i] = sum;
}
for ( int i = 0; i < n; i++) {
Console.Write(arr[i] + " " );
}
}
} } // This code is contributed by Prajwal Kandekar |
// Function to replace every element of the array to the sum of elements on the right side of the array function replaceElement(arr) {
for (let i = 0; i < arr.length; i++) {
let sum = 0;
for (let j = i + 1; j < arr.length; j++) {
sum += arr[j];
}
arr[i] = sum;
}
console.log(arr.join( " " ));
} // Driver code to test above function let arr = [1, 2, 5, 2, 2, 5]; replaceElement(arr); |
Output
16 14 9 7 5 0
Time Complexity: O(N^2)
Auxiliary Space : O(1)
Efficient Approach: The idea is to compute the total sum of the array and then update the current element as the
for i in arr: arr[i] = sum - arr[i] sum = arr[i]
Below is the implementation of the above approach:
// C++ program to Replace every // element of array with sum of // elements on its right side #include<bits/stdc++.h> using namespace std;
// Function to replace every element // of the array to the sum of elements // on the right side of the array void replaceElement( int arr[], int n)
{ int sum = 0;
// Calculate sum of all
// elements of array
for ( int i = 0; i < n; i++)
sum += arr[i];
// Traverse the array
for ( int i = 0; i < n; i++)
{
// Replace current element
// of array with sum-arr[i]
arr[i] = sum - arr[i];
// Update sum with arr[i]
sum = arr[i];
}
// Print modified array
for ( int i = 0; i < n; i++)
cout << arr[i] << " " ;
} // Driver code int main()
{ int arr[] = { 1, 2, 5, 2, 2, 5 };
int n = sizeof (arr) / sizeof (arr[0]);
replaceElement(arr, n);
} // This code is contributed by Surendra_Gangwar |
// Java program to Replace every // element of array with sum of // elements on its right side import java.util.*;
class GFG {
// Function to replace every element
// of the array to the sum of elements
// on the right side of the array
static void replaceElement( int [] arr, int n)
{
int sum = 0 ;
// Calculate sum of all
// elements of array
for ( int i = 0 ; i < n; i++)
sum += arr[i];
// Traverse the array
for ( int i = 0 ; i < n; i++) {
// Replace current element
// of array with sum-arr[i]
arr[i] = sum - arr[i];
// Update sum with arr[i]
sum = arr[i];
}
// Print modified array
for ( int i = 0 ; i < n; i++)
System.out.print(arr[i] + " " );
}
// Driver code
public static void main(String[] args)
{
int [] arr = { 1 , 2 , 5 , 2 , 2 , 5 };
int n = arr.length;
replaceElement(arr, n);
}
} |
# Python3 program to replace every # element of array with sum of # elements on its right side # Function to replace every element # of the array to the sum of elements # on the right side of the array def replaceElement(arr, n):
sum = 0 ;
# Calculate sum of all
# elements of array
for i in range ( 0 , n):
sum + = arr[i];
# Traverse the array
for i in range ( 0 , n):
# Replace current element
# of array with sum-arr[i]
arr[i] = sum - arr[i];
# Update sum with arr[i]
sum = arr[i];
# Print modified array
for i in range ( 0 , n):
print (arr[i], end = " " );
# Driver Code if __name__ = = "__main__" :
arr = [ 1 , 2 , 5 , 2 , 2 , 5 ]
n = len (arr)
replaceElement(arr, n)
# This code is contributed by Ritik Bansal |
// C# program to Replace every // element of array with sum of // elements on its right side using System;
class GFG{
// Function to replace every element // of the array to the sum of elements // on the right side of the array static void replaceElement( int [] arr, int n)
{ int sum = 0;
// Calculate sum of all
// elements of array
for ( int i = 0; i < n; i++)
sum += arr[i];
// Traverse the array
for ( int i = 0; i < n; i++)
{
// Replace current element
// of array with sum-arr[i]
arr[i] = sum - arr[i];
// Update sum with arr[i]
sum = arr[i];
}
// Print modified array
for ( int i = 0; i < n; i++)
Console.Write(arr[i] + " " );
} // Driver code public static void Main()
{ int [] arr = { 1, 2, 5, 2, 2, 5 };
int n = arr.Length;
replaceElement(arr, n);
} } // This code is contributed by Nidhi_biet |
<script> // JavaScript program to Replace every // element of array with sum of // elements on its right side // Function to replace every element // of the array to the sum of elements // on the right side of the array function replaceElement(arr, n)
{ let sum = 0;
// Calculate sum of all
// elements of array
for (let i = 0; i < n; i++)
sum += arr[i];
// Traverse the array
for (let i = 0; i < n; i++)
{
// Replace current element
// of array with sum-arr[i]
arr[i] = sum - arr[i];
// Update sum with arr[i]
sum = arr[i];
}
// Print modified array
for (let i = 0; i < n; i++)
document.write(arr[i] + " " );
} // Driver code let arr = [ 1, 2, 5, 2, 2, 5 ];
let n = arr.length;
replaceElement(arr, n);
//This code is contributed by Mayank Tyagi </script> |
Output:
16 14 9 7 5 0
Time Complexity: O(N)
Auxiliary Space: O(1)