std::move

Lab C++ Advanced 30 points

Read n words into a vector a. Then vector<string> b = std::move(a);. Print the size of b, its contents joined by commas, and the size of a after a.clear().

Input

n, then n words.

Output

Three lines.

Example

Input

3
red green blue

Output

3
red,green,blue
0

Sample input available Sample output available

Editor

C++

Hints

Moving transfers the contents instead of copying them.

A moved-from object is valid but unspecified - clear it before reuse.

Solution explanation

Move semantics make returning and passing big objects cheap.

Show solution

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

int main() {
    int n;
    cin >> n;
    vector<string> a(n);
    for (auto &w : a) cin >> w;
    vector<string> b = std::move(a);
    a.clear();
    cout << b.size() << "\n";
    for (size_t i = 0; i < b.size(); i++) cout << b[i] << (i + 1 < b.size() ? "," : "\n");
    cout << a.size() << "\n";
    return 0;
}

Output

Answer