Submission #805695

#	Time	Username	Problem	Language	Result	Execution time	Memory
805695		farhan132	Chessboard (IZhO18_chessboard)	C++17	100 / 100	1181 ms	6384 KiB

chessboard

/***Farhan132***/
// #pragma GCC optimize("Ofast,fast-math")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
// #pragma GCC optimization ("unroll-loops")

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef double dd;
typedef pair<ll , ll> ii;
typedef tuple < ll,  ll, ll > tp;
 
#define ff first
#define ss second
#define pb push_back
#define in insert
#define bug printf("**!\n")
#define mem(a , b) memset(a, b ,sizeof(a))
#define front_zero(n) __builtin_clz(n)
#define back_zero(n) __builtin_ctzll(n)
#define total_one(n) __builtin_popcount(n)
#define clean fflush(stdout)
 
const ll mod =  (ll) 998244353;
// const ll mod =  (ll) 1e9 + 7;
//const ll INF = numeric_limits<ll>::max()-1;
const ll INF = (ll)2e18;
 
// ll dx[]={0,1,0,-1};
// ll dy[]={1,0,-1,0};
// ll dxx[]={0,1,0,-1,1,1,-1,-1};
// ll dyy[]={1,0,-1,0,1,-1,1,-1};
 
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
 
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ll N = 2005;

ii add(ii a, ii b){
    return {a.ff + b.ff, a.ss + b.ss};
}
ii sub(ii a, ii b){
    return {a.ff - b.ff, a.ss - b.ss};
}

ii f(ll col, ll h, ll sz, ll n){
    ll nor = n / (2 * sz);
    ii ans = {nor * sz, nor * sz};
    n %= (2 * sz);
    if(n > sz){
        ans.ff += sz;
        ans.ss += n - sz;
    }else{
        ans.ff += n;
    }
    ans.ff *= h;
    ans.ss *= h;
    if(!col) swap(ans.ff, ans.ss);
    return ans;
}

ii corner(ll x, ll y, ll sz){
    if(min(x, y) < 1) return {0, 0}; 
    ll p1 = x / sz;
    ll p2 = y / sz;
    ll unit = sz * sz;
    ii ans = {unit * ((p1 * p2 + 1) / 2), unit * ((p1 * p2) / 2)};

    ans = add(ans, f(1 - p1%2, x % sz, sz, y));
    ans = add(ans, f(1 - p2%2, y % sz, sz, p1 * sz));
    return ans;
}
ii F(ll r1, ll c1, ll r2, ll c2, ll sz){
    ii ans = corner(r2, c2, sz);
    ans = sub(ans, corner(r2, c1 - 1, sz));
    ans = sub(ans, corner(r1 - 1, c2, sz));
    ans = add(ans, corner(r1 - 1, c1 - 1, sz));
    return ans;
}

void solve(){

    ll n; cin >> n; 

    vector < tuple < ll , ll , ll , ll > > Q;

    ll q; cin >> q;
    for(ll i = 0; i < q; i++){
        ll r1, c1, r2, c2;
        cin >> r1 >> c1 >> r2 >> c2;
        Q.push_back({r1, c1, r2, c2});
    }
    ll ans = n * n;

    for(ll sz = 1; sz < n; sz++){
        if(n % sz != 0) continue;
        ii cnt = {0, 0};
        for(auto [r1, c1, r2, c2] : Q){
            cnt = add(cnt, F(r1, c1, r2, c2, sz));
        }
        ii overall = corner(n, n, sz);
        ans = min({ans, cnt.ss + overall.ff - cnt.ff, cnt.ff + overall.ss - cnt.ss});
    }
    cout << ans << '\n';
    
   return;
}

int main() {

    #ifdef LOCAL
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
        auto start_time = clock();
    #else
         // freopen("subsequence.in", "r", stdin);
         // freopen("subsequence.out", "w", stdout); 
         ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
    #endif

    //precalc();
 
    ll T = 1, CT = 0; //cin >> T; 
 
    while(T--){
        // cout << "Case #" << ++CT << ": ";
        solve();
    }
    
    #ifdef LOCAL
        auto end_time = clock();
        cerr<< "Execution time: "<<(end_time - start_time)*(int)1e3/CLOCKS_PER_SEC<<" ms\n";
    #endif
 
    return 0;
} 

Compilation message (stderr)

chessboard.cpp: In function 'int main()':
chessboard.cpp:130:15: warning: unused variable 'CT' [-Wunused-variable]
  130 |     ll T = 1, CT = 0; //cin >> T;
      |               ^~

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 23 / 23
• Subtask 6: 30 / 30