[C++ Primer] 练习3.20

#include <iostream>
#include <vector>

using std::vector;
using std::string;
using std::cin;
using std::cout;
using std::endl;

int main() {
    //Clion EOF不起作用，使用指定vector代替输入
    vector<int> numbers{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
    int size = numbers.size();
    if (size > 1) {
        for (int i = 0; i < size / 2; i++) {
            cout << numbers[i] + numbers[size - 1 - i] << " ";
        }
        cout << endl;
    } else if (size == 1) {
        cout << numbers[0] << endl;
    } else {
        cout << "no intput numbers" << endl;
    }
    return 0;
}