Submission #1108501

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108501		KasymK	Chessboard (IZhO18_chessboard)	C++17	100 / 100	396 ms	6760 KiB

chessboard

#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const ll INF = 1e18;
#define int long long
using node = tuple<int, int, int, int>;
int answer = INF;
vector<node> adj;
int n, kk;
 
int f(int x, int y, int xx){
    int sm = 0, _x = (x/xx)*xx, _y = (y/xx)*xx;
    if((_x/xx+_y/xx)&1){
        sm += ((_x/xx)*(_y/xx))/2*(xx*xx);
        sm += (_y/xx+1)/2*(x-_x)*xx;
        sm += (_x/xx+1)/2*(y-_y)*xx;
    }
    else{
        sm += ((_x/xx)*(_y /xx)+1)/2*(xx*xx);
        sm += (_y/xx)/2*(x-_x)*xx;
        sm += ((_x/xx))/2*(y-_y)*xx;
        sm += (x-_x)*(y-_y);
    }
    return sm;
}
 
void solve(int x){
    int ans = n*n-f(n, n, x);
    for(auto xx : adj){
        int a, b, c, d;
        tie(a, b, c, d) = xx;
        int w = f(c, d, x)+f(a-1, b-1, x)-f(c, b-1, x)-f(a-1, d, x);
        ans += w, ans -= (c-a+1)*(d-b+1)-w;
    }
    umin(answer, ans);
    umin(answer, n*n-ans);
}
 
signed main(){
    // freopen("file.txt", "r", stdin);
    scanf("%lld%lld", &n, &kk);
    bool done = 1;
    for(int i = 1; i <= kk; ++i){
        int a, b, c, d;
        scanf("%lld%lld%lld%lld", &a, &b, &c, &d);
        adj.pb({a, b, c, d});
        done |= (a==c and b==d);
    }
    assert(done);
    for(int i = 1; i*i <= n; ++i){
        if(n%i==0){
        solve(i);
        if(i!=n/i and i>1)
            solve(n/i);
        }
    }
    printf("%lld\n", answer);
    return 0;
}

Compilation message (stderr)

chessboard.cpp: In function 'int main()':
chessboard.cpp:52:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |     scanf("%lld%lld", &n, &kk);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
chessboard.cpp:56:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         scanf("%lld%lld%lld%lld", &a, &b, &c, &d);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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