Vector Basics

Lab C++ Beginner 10 points

Read n integers into a vector<int> with push_back. Print the size, the first and last elements, and the elements in reverse.

Input

Line 1: n. Line 2: n integers.

Output

Four lines.

Example

Input

5
1 2 3 4 5

Output

Sample input available Sample output available

Editor

C++

Hints

push_back appends; front() and back() read the ends.

Solution explanation

A vector grows automatically and knows its own size.

Show solution

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

int main() {
    int n;
    cin >> n;
    vector<int> v;
    for (int i = 0; i < n; i++) {
        int x;
        cin >> x;
        v.push_back(x);
    }
    cout << v.size() << "\n" << v.front() << "\n" << v.back() << "\n";
    for (int i = (int) v.size() - 1; i >= 0; i--) cout << v[i] << (i > 0 ? " " : "\n");
    return 0;
}

Output

Answer