题解 | #尼科彻斯定理#

#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main() {
    int m = 0;
    cin >> m;
    vector<int> arr;
    for (int i = 0; i < 2*m; i += 2)
    {
        arr.push_back(m*m-m+1 + i);//观察规律得到首个奇数位置
    }
    for (int i = 0; i < arr.size()-1; ++i)
    {
        cout << to_string(arr[i]) << '+';  
    }
    cout << arr[arr.size()-1];
    return 0;
}