Submission #334523

#	Time	Username	Problem	Language	Result	Execution time	Memory
334523		tengiz05	Chessboard (IZhO18_chessboard)	C++17	100 / 100	1942 ms	8220 KiB

chessboard

#pragma GCC optimize("O3") 
#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;
}
 
#define vl vector <ll> 
 
const int N = 1e5+7;
ll n, k;
 
inline ll rect_size(ll x1, ll y1, ll x2, ll y2){
    return (x2-x1+1)*(y2-y1+1);
}
 
inline ll pref(ll x, ll y, ll div){
    ll res = 0;
    ll x_1_mod_div = (x+1)%div, y_1_mod_div = (y+1)%div;
    ll x_full = x-x_1_mod_div, y_full = y-y_1_mod_div;
    ll full_s1 = (x_full+1)/div, full_s2 = (y_full+1)/div;
    ll x_full_div = (x_full+1)/div, y_full_div = (y_full+1)/div;
    
    res += ((full_s1*full_s2)&1 ? full_s1*full_s2/2+1 : full_s1*full_s2/2)*div*div;
    
    ll tmp;
    if((y_full_div)&1){
        int flag = x/div+y_full/div;
        if(flag&1){
            res += (x_1_mod_div)*(y_full_div/2)*div;
        }
        else{
            res += (x_1_mod_div)*(y_full_div/2+1)*div;
        }
    }
    else{
        tmp = (y_full+1)/2*(x_1_mod_div);
        res += tmp;
    }
    if((x_full_div)&1){
        int flag = y/div+x_full/div;
        if(flag&1){
            res += (y_1_mod_div)*(x_full_div/2)*div;
        }
        else{
            res += (y_1_mod_div)*(x_full_div/2+1)*div;
        }
    }
    else{
        tmp = (x_full+1)/2*(y_1_mod_div);
        res += tmp;
    }
    
    int flag = x/div+y/div;
    if(!(flag&1)){
        res += rect_size(x_full+1, y_full+1, x, y);
    }
    
    return res;
}
 
inline ll calc1(ll div, vl x1, vl y1, vl x2, vl y2){
    ll to_white = 0, to_black = ((n*n/div/div)&1 ? (n*n/div/div/2+1)*div*div : (n*n/2));
    for(ll i = 0; i < k; i++){
        ll blacks_in = pref(x2[i], y2[i], div)-(x1[i]-1 > -1 ? pref(x1[i]-1, y2[i], div) : 0)-(y1[i]-1 > -1 ? pref(x2[i], y1[i]-1, div) : 0)+
                      ((x1[i]-1 > -1) && (y1[i]-1 > -1) ? pref(x1[i]-1, y1[i]-1, div) : 0);
        to_black -= blacks_in;
        to_white += rect_size(x1[i], y1[i], x2[i], y2[i])-blacks_in;
    }
    
    return to_white+to_black;
}
 
int main(){
    do_not_disturb
    
    ll ans = 2e18, i;
    cin >> n >> k;
    vector <ll> x1(k), y1(k), x2(k), y2(k);
    
    for(i = 0; i < k; i++){
        cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
        x1[i]--; y1[i]--; x2[i]--; y2[i]--;
    }
    
    for(i = 1; i*i <= n; i++){
        if(n%i == 0){
            auto tmp = calc1(i, x1, y1, x2, y2);
            ans = min(ans, min(tmp, n*n-tmp));
            if(i > 1){
                tmp = calc1(n/i, x1, y1, x2, y2);
                ans = min(ans, min(tmp, n*n-tmp));
            }
        }
    }
    
    cout << ans;
    
    return 0;
}

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