Templates and Iterators

Lab C++ Advanced 30 points

Write template <typename It> auto sumRange(It first, It last) that adds the elements in [first, last). Use it on a whole vector of ints, on the first half of it, and on a vector of doubles.

Input

Line 1: n then n ints. Line 2: m then m decimals.

Output

Three lines (the double sum with 2 decimals).

Example

Input

4 1 2 3 4
2 0.5 0.25

Output

10
3
0.75

Sample input available Sample output available

Editor

C++

Hints

Iterators are what STL algorithms use to describe ranges.

*first - *first is a zero of the right type.

Solution explanation

Writing algorithms against iterators makes them work with any container.

Show solution

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

template <typename It>
auto sumRange(It first, It last) {
    auto total = *first - *first;
    for (It it = first; it != last; ++it) total += *it;
    return total;
}

int main() {
    int n, m;
    cin >> n;
    vector<long long> a(n);
    for (auto &x : a) cin >> x;
    cin >> m;
    vector<double> b(m);
    for (auto &x : b) cin >> x;
    cout << sumRange(a.begin(), a.end()) << "\n";
    cout << sumRange(a.begin(), a.begin() + n / 2) << "\n";
    cout << fixed << setprecision(2) << sumRange(b.begin(), b.end()) << "\n";
    return 0;
}

Output

Answer