C++ code

答案在下↓

C++ code:

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