39H - Multiplication Table - CodeForces Solution

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define vll vector<ll>
#define vld vector<ld>
#define vi vector<int>
#define forn(i, n) for(int i = 0; i < int(n); ++i)
#define all(x)  x.begin(), x.end()
ll mod=998244353;
int INF=1E9;
ll LLINF=1E18;
using namespace std;
//#define cin fin
//#define cout fout
ifstream fin("search.in");
ofstream fout("search.out");
#define znakposlezapjtoi  cout << fixed; cout.precision(10);
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n;
    cin>>n;
    forn(i,n-1) cout<<i+1<<" ";
    cout<<"\n";
    for (int j=2;j<n;j++) {
        cout<<j<<" ";
        for (int i=2;i<n;i++) {
            int x=i*j;
            vi v;
            while (x!=0) {
                v.push_back(x%n);
                x/=n;
            }
            reverse(all(v));
            for (auto i:v) cout<<i;
            cout<<" ";
        }
        cout<<"\n";
    }
}