Use for_each() algorithm to show elements in a vector and do the summation : for_each « STL Algorithms Non modifying sequence operations « C++ Tutorial

1. C++ Tutorial
2. STL Algorithms Non modifying sequence operations
3. for_each

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

void show(int i) {
  cout << i << endl;
}

// A running sum.
int summation(int i) {
  static int sum = 0;

  sum += i;
  return sum;
}

int main()
{
  vector<int> v;
  int i;

  for(i=1; i < 11; i++) v.push_back(i);

  for_each(v.begin(), v.end(), show);

  for_each(v.begin(), v.end(), summation);
  
  cout << summation(0);

  return 0;
}