urgenttt! rezolvati problema în c++

#include <iostream>
using namespace std;
int main(){
int n, a[40][40],i,j,par,imp;
cin >> n;
imp=1;
par=n*n;
if(par%2==1)par--;
//Construire
for(i=1;i<=n;i+=2)
for(j=1;j<=n;j++){
a[i][j] = imp;
imp+=2;
}
for(i=2;i<=n;i+=2)
for(j=1;j<=n;j++){
a[i][j] = par;
par-=2;
}
//Afisare matrice
for(i=1;i<=n;i++){
for(j=1;j<=n;j++) cout << a[i][j] << " ";
cout << endl;
}
}