Submission #880803

#	Time	Username	Problem	Language	Result	Execution time	Memory
880803		dimashhh	Chessboard (IZhO18_chessboard)	C++17	70 / 100	803 ms	161872 KiB

chessboard

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 1;

#define int long long
int odd[N][101],even[N][101],it = 0;
ll col_eq(int k,int x,int y,int x1,int y1){
    ll ret = (odd[x1][k] - odd[x - 1][k]) * (odd[y1][k] - odd[y - 1][k]);
    ret += (even[x1][k] - even[x - 1][k]) *1ll* (even[y1][k] - even[y - 1][k]);
    return ret;
}
ll col_non_eq(int k,int x,int y,int x1,int y1){
    return (x1 - x + 1) *1ll* (y1 - y + 1) - col_eq(k,x,y,x1,y1);
}
vector<pair<pair<int,int>,pair<int,int>>> a;
ll n,k;
int get(ll del,ll i){
    ll res1 = 0,res2 = 0;
    for(auto [x,y]:a){
        res1 += col_eq(i,x.first,x.second,y.first,y.second);
        res2 += col_non_eq(i,x.first,x.second,y.first,y.second);
    }
    ll x = res1;
    res1 = ((n * n / del / del) + 1) / 2 * (del * del) - res1 + res2;
    res2 = ((n * n / del / del)) / 2 * (del * del) + x - res2;
    // cout << ((n * n / del / del) + 1) / 2 * del * del - res2 << '\n';
    return min(res1,res2);
}
void test(){
    cin >> n >> k;
    for(int i = 1;i <= k;i++){
        int x,y,x1,y1;
        cin >> x >> y >> x1 >> y1;
        a.push_back({{x,y},{x1,y1}});
    }
    ll res = 1e10;
    for(int i = 1;i < n;i++){
        if(n % i == 0){
            for(int j = 1;j <= n;j++){
                int x = (j + i - 1) / i;
                odd[j][it] = odd[j - 1][it];
                even[j][it] = even[j - 1][it];
                if(x & 1){
                    odd[j][it]++;
                }else{
                    even[j][it]++;
                }
            }
            it++;
        }
    }
    it = 0;
    for(int i = 1;i < n;i++){
        if(n % i == 0){
            res = min(res,1ll*get(i,it));
            it++;
        }
    }
    cout << res;
}
main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    test();
}

Compilation message (stderr)

chessboard.cpp:62:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   62 | main(){
      | ^~~~

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