How to find the sum of elements of a Vector using STL in C++?
Given a vector, find the sum of the elements of this vector using STL in C++.
Example:
Input: vec = {1, 45, 54, 71, 76, 12} Output: 259 Input: vec = {1, 7, 5, 4, 6, 12} Output: 35
Approach: Sum can be found with the help of accumulate() function provided in STL.
Syntax:
accumulate(first_index, last_index, initial value of sum);
Time Complexity: It is linear in the distance between first_index and last_index i.e if your vector contains n number of elements between two given indices , the time complexity will be O(n).
CPP
// C++ program to find the sum // of Array using accumulate() in STL #include <bits/stdc++.h> using namespace std; int main() { // Get the vector vector< int > a = { 1, 45, 54, 71, 76, 12 }; // Print the vector cout << "Vector: " ; for ( int i = 0; i < a.size(); i++) cout << a[i] << " " ; cout << endl; // Find the sum of the vector cout << "\nSum = " << accumulate(a.begin(), a.end(), 0); return 0; } |
Output:
Vector: 1 45 54 71 76 12 Sum = 259