Submission #334325

#	Time	Username	Problem	Language	Result	Execution time	Memory
334325		talant117408	Chessboard (IZhO18_chessboard)	C++17	70 / 100	2089 ms	5972 KiB

chessboard

/*
    Code written by Talant I.D.
*/
  
#include <bits/stdc++.h>
  
using namespace std;
  
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
  
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
  
inline bool isvowel(char ch){
    ch = tolower(ch);
    return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u');
}
  
inline bool isprime(int n){
    if(n < 2 || (n%2 == 0 && n != 2)) return false;
    for(int i = 3; i*i <= n; i++)
        if(n%i == 0) return false;
    return true;
}
 
class Union{
    private:
        vector <int> saizu, link;
    public:
        Union(int n){
            saizu.assign(n, 1); link.resize(n); 
            iota(all(link), 0);
        }
        int find(int n){
            if(link[n] == n) return n;
            return link[n] = find(link[n]);
        }
        int same(int a, int b){
            return find(a) == find(b);
        }
        void unite(int a, int b){
            if(same(a, b)) return;
             
            a = find(a); b = find(b);
            if(saizu[a] < saizu[b]) swap(a, b);
             
            saizu[a] += saizu[b];
            link[b] = a;
        }
        int getsize(int a){
            return saizu[find(a)];
        }
};
 
const int mod = 1e9+7;
 
ll mode(ll a){
    a %= mod;
    if(a < 0) a += mod;
    return a;
}
 
ll subt(ll a, ll b){
    return mode(mode(a)-mode(b));
}
 
ll add(ll a, ll b){
    return mode(mode(a)+mode(b));
}
 
ll mult(ll a, ll b){
    return mode(mode(a)*mode(b));
}
 
ll binpow(ll a, ll b){
    ll res = 1;
    while(b){
        if(b&1) res = mult(res, a);
        a = mult(a, a);
        b >>= 1;
    }
    return res;
}

int main(){
    do_not_disturb
    
    ll n, k, ans = 9e18;
    cin >> n >> k;
    ll x1[k], y1[k], x2[k], y2[k];
    for(ll i = 0; i < k; i++){
        cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
        x1[i]--; y1[i]--; x2[i]--; y2[i]--;
    }
    
    for(ll i = 1; i*i <= n; i++){
        if(n%i == 0){
            ll to_white = 0, to_black = ((n*n/i/i)&1 ? (n*n/i/i/2+1)*i*i : (n*n/2));
            
            for(ll j = 0; j < k; j++){
                for(ll w = x1[j]; w <= x2[j]; w++){
                    for(ll o = y1[j]; o <= y2[j]; o++){
                           ll cnt = w/i+o/i;
                           if(cnt%2 == 0){
                               to_black--;
                           }
                           else{
                               to_white++;
                           }
                    }
                }
            }
            ans = min(ans, to_black+to_white);
            
            to_white = 0, to_black = (n*n/i/i/2);
            to_black *= i*i;
            
            for(ll j = 0; j < k; j++){
                for(ll w = x1[j]; w <= x2[j]; w++){
                    for(ll o = y1[j]; o <= y2[j]; o++){
                           ll cnt = w/i+o/i;
                           if(cnt%2 == 0){
                               to_white++;
                           }
                           else{
                               to_black--;
                           }
                    }
                }
            }
            ans = min(ans, to_black+to_white);
            
            if(i == 1) continue;
            ll q = i; 
            i = n/i;
            
            to_white = 0, to_black = ((n*n/i/i)&1 ? (n*n/i/i/2+1)*i*i : (n*n/2));
            
            for(ll j = 0; j < k; j++){
                for(ll w = x1[j]; w <= x2[j]; w++){
                    for(ll o = y1[j]; o <= y2[j]; o++){
                           ll cnt = w/i+o/i;
                           if(cnt%2 == 0){
                               to_black--;
                           }
                           else{
                               to_white++;
                           }
                    }
                }
            }
            ans = min(ans, to_black+to_white);
            
            to_white = 0, to_black = (n*n/i/i/2);
            to_black *= i*i;
            
            for(ll j = 0; j < k; j++){
                for(ll w = x1[j]; w <= x2[j]; w++){
                    for(ll o = y1[j]; o <= y2[j]; o++){
                           ll cnt = w/i+o/i;
                           if(cnt%2 == 0){
                               to_white++;
                           }
                           else{
                               to_black--;
                           }
                    }
                }
            }
            ans = min(ans, to_black+to_white);
            i = q;
        }
    }
    
    cout << ans << endl;
    
    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 23 / 23
• Subtask 6: 0 / 30