1266C - Diverse Matrix - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define vbe(v,n,m) v.begin()+n,v.begin()+m
#define int long long
#define fi first
#define sec second
const int mod=1e9+7;
const int N=1e5+7;
#define cy cout<<"YES"<<"\n"
#define cn cout<<"NO"<<"\n"
#define ch(n) cout<<"hello-"<<n<<"\n"
#define cot(n) cout<<n<<"\n"
#define ret(n) cout<<n<<"\n";return
#define print(v) for(auto &it:v){cout<<it<<' ';}cout<<"\n";
 
void judge(){
    #ifndef ONLINE_JUDJE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
}

void solve(){

    int r, c;
    cin >> r >> c;

    if(r==1 && c==1){
        ret(0);
    }
    /////////////////////////////////////////////////////////////////////
    if(r==1){
        int ct = 2;
        for (int i = 0; i < c;i++){
            cout << ct <<' ';
            ct++;
        }
        return;
    }
    else if(c==1){
        int ct = 2;
        for (int i = 0; i < r;i++){
            cout << ct << '\n'; 
            ct++;
        }
        return;
    }
    /////////////////////////////////////////////////////////////////////
    bool cc = false;
    bool rr = false;
    if(c<r){
        cc = true;
    }
    else if(c>r){
        rr = true;
        // ch(66);
    }
    vector<int> row(c, 0);
    row[0] = 2;
    row[1] = 3;
    for (int i = 2; i < c;i++){
        if(rr && row[i-1]>=(2*r)){
            row[i] = row[i - 1] + 1;
        }
        else{
          row[i] = row[i - 1] + 2;
        }
    }
    /////////////////////////////////////////////////////////////////////
    vector<int> col(r, 0);
    col[0] = 1;
    col[1] = 4;
    for (int i = 2; i < r;i++){
        if(cc && col[i-1]>=2*c){
            col[i] = col[i - 1] + 1;
        }
        else{
           col[i] = col[i - 1] + 2;
        }
    }
    /////////////////////////////////////////////////////////////////////
    for (int i = 0; i < r;i++){
        for (int j = 0; j < c;j++){
            cout << row[j] * col[i] << ' ';
        }
        cout << '\n';
    }
    //////////////////////////////////////////////////////////////////////
}
 
signed main()
{
    
    //judge();
    
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    // int test=0;
    // cin>>test;
    // while (test--){
        solve();
    // }
 return 0;
}