How to Find the Sum of All Elements in a Deque in C++?

In C++, double-ended queues are sequence containers similar to vectors but are more efficient in the case of insertion and deletion of elements at both ends. In this article, we will learn how to find the sum of all elements in a deque in C++.

Example

Input:
myDeque ={1,2,3,4,5}

Output:
Sum of all deque elements is 15.

Sum Up All Elements of a Deque in C++

To find the sum of all the elements in a std::deque in C++, we can use the std::accumulate() method which finds the sum of the elements in the given range.

Syntax

accumulate(first, last, 0);

where,

• first : Iterator pointing to the beginning of the deque.
• last : Iterator pointing to one position past the end of the deque.
• 0: Initial value for the sum.

C++ Program to Find the Sum of All Elements in a Deque

The following program illustrates how we can find the sum of all elements in a deque in C++:

C++

// C++ Program to illustrate how to find the sum of all
// elements in a deque
#include <deque>
#include <iostream>
#include <numeric>
using namespace std;

int main()
{
    // Initialize the deque
    deque<int> dq = { 1, 2, 3, 4, 5 };

    // Print elements of the deque
    cout << "Deque Elements: ";
    for (int x : dq) {
        cout << x << " ";
    }
    cout << endl;

    // Use accumulate to find the sum of all elements
    int sum = accumulate(dq.begin(), dq.end(), 0);

    // Print the sum of ell elemetns in the deque
    cout << "Sum of elements in the Deque: " << sum;

    return 0;
}

Output

Deque Elements: 1 2 3 4 5 
Sum of elements in the Deque: 15

Time Complexity: O(N) here N denotes the size of the deque.
Auxiliary Space: O(1)