题解 | 小红的不动点构造

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n, k;
    cin >> n >> k;
    if (abs(n - k) == 1)
        cout << "-1";
    else if(n != k)
    {
        for (int i = 1; i <= k; i++)
            cout << i << " ";
        for (int i = k + 2; i <= n; i++)
            cout << i << " ";
        cout << k + 1;
    }
    else 
    {
        for (int i = 1; i <= k; i++)
            cout << i << " ";
        for (int i = k + 2; i <= n; i++)
            cout << i << " ";
    }
    
    return 0;
}

看数据特判这一块。