Computing the Sum and Mean of Elements in a Container with accumulate template function - C++ STL Algorithm

C++ examples for STL Algorithm:accumulate

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Description

Computing the Sum and Mean of Elements in a Container with accumulate template function

Demo Code

#include <numeric>
#include <iostream>
#include <vector>

using namespace std;

int main() {//from  ww w .jav a 2 s .c o  m
  vector<int> v;
  v.push_back(1);
  v.push_back(2);
  v.push_back(3);
  v.push_back(4);
  
  int sum = accumulate(v.begin(), v.end(), 0);
  
  double mean = double(sum) / v.size();
  
  cout << "sum = " << sum << endl;
  cout << "count = " << v.size() << endl;
  cout << "mean = " << mean << endl;
}

Result

A generic function to compute the mean 

template<class Iter_T>
double computeMean(Iter_T first, Iter_T last) {
  return static_cast<double>(accumulate(first, last, 0.0))/ distance(first, last);
}

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