Submission #683115

#	Time	Username	Problem	Language	Result	Execution time	Memory
683115		Ronin13	Chessboard (IZhO18_chessboard)	C++14	70 / 100	385 ms	4224 KiB

chessboard

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define f first
#define s second
#define pii pair<ll,ll>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
using namespace std;
/*
6 8
3 3 3 3
1 2 1 2
3 4 3 4
5 5 5 5
4 3 4 3
4 4 4 4
2 1 2 1
3 6 3 6
*/
int main(){
  //  freopen("school.in", "r", stdin);
 // freopen("school.out", "w", stdout);
    int n, k;
    cin >> n >> k;
    int x1[k + 1], x2[k + 1], y1[k + 1], y2[k + 1];
    for(int i =  1; i <= k; ++i){
        cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
        x1[i]--;
        y1[i]--;
        x2[i]--;
        y2[i]--;
    }
    ll ans = 1e18 + 1;
    for(ll a = 1; a <n; a++){
        if(n % a) continue;
        ll v = n / a;
        ll cnt = 0;
        if(v % 2 == 1)
            cnt += v * (v / 2) + (v + 1)  / 2;
        else cnt = v * v / 2;
        cnt *= a * a;
        for(int i = 1; i <= k; i++){
            int X = x1[i] / a, Y = y1[i] / a;
            if((X + Y) & 1)
                cnt++;
            else cnt--;
        }
        ans = min(ans, cnt);
    }
    for(ll a = 1; a <n; a++){
        if(n % a) continue;
        ll v = n / a;
        ll cnt = -1;
        if(v % 2 == 1)
            cnt += v * (v / 2) + (v + 1) / 2;
        else cnt = v * v / 2;
        cnt *= a * a;
        for(int i = 1; i <= k; i++){
            int X = x1[i] / a, Y = y1[i] / a;
            if((X + Y) & 1)
                cnt--;
            else cnt++;
        }
        ans = min(ans, cnt);
    }
    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: 0 / 30