Submission #844084

#	Time	Username	Problem	Language	Result	Execution time	Memory
844084		Darren0724	Chessboard (IZhO18_chessboard)	C++17	100 / 100	744 ms	704 KiB

chessboard

#include <bits/stdc++.h>
using namespace std;
#define int long long
int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n,q;cin>>n>>q;
    
    vector<int> v;
    vector<int> a[2];
    for(int i=1;i<n;i++){
        if(n%i==0){
            v.push_back(i);
            int p=n/i;
            if(p&1){
                a[0].push_back((p*p-1)*i*i/2);
                a[1].push_back((p*p+1)*i*i/2);
            }
            else{
                a[0].push_back(n*n/2);
                a[1].push_back(n*n/2);
            }
        }
    }
    auto solve=[&](int a,int b,int c,int d,int k)->long long {
        if(c<a||d<b){
            return 0;
        }
        int a1=a/k;
        int b1=b/k;
        int c1=c/k;
        int d1=d/k;
        int ans=0;
        if((d1-b1)*(c1-a1)%2==1){
            if((a1^b1)&1){
                ans+=k*k;
            }
            else{
                ans-=k*k;
            }
        }
        int up=c-c1*k+1;
        int right=d-d1*k+1;
        if((c1-a1)%2==1){
            if((a1^d1)&1){
                ans+=k*right;
            }
            else{
                ans-=k*right;
            }
        }
        if((d1-b1)%2==1){
            if((b1^c1)&1){
                ans+=k*up;
            }
            else{
                ans-=k*up;
            }
        }
        if((c1^d1)&1){
            ans+=up*right;
        }
        else{
            ans-=up*right;
        }
        //cout<<a<<' '<<b<<' '<<c<<' '<<d<<' '<<ans<<'\n';
        return ans;
    };
    int sz=v.size();
    for(int i=0;i<q;i++){
        int c,d,e,f;
        cin>>c>>d>>e>>f;
        c--;d--;e--;f--;
        for(int j=0;j<sz;j++){
            int k=v[j];
            int c1=c/k;
            int d1=d/k;
            int e1=e/k;
            int f1=f/k;
            int t=solve(c1*k,d1*k,e,f,k)-solve(c1*k,d1*k,c-1,f,k)-solve(c1*k,d1*k,e,d-1,k)+solve(c1*k,d1*k,c-1,d-1,k);
            //cout<<t<<'\n';
            a[0][j]-=t;
            a[1][j]+=t;
        }
    }
    int ans=n*n;
    for(int j=0;j<sz;j++){
        ans=min(ans,a[0][j]);
        ans=min(ans,a[1][j]);
        //cout<<v[j]<<' '<<a[0][j]<<' '<<a[1][j]<<endl;
    }
    cout<<ans<<endl;


    return 0;
}
/*
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
*/

Compilation message (stderr)

chessboard.cpp: In function 'int32_t main()':
chessboard.cpp:78:17: warning: unused variable 'e1' [-Wunused-variable]
   78 |             int e1=e/k;
      |                 ^~
chessboard.cpp:79:17: warning: unused variable 'f1' [-Wunused-variable]
   79 |             int f1=f/k;
      |                 ^~

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