Submission #334381

#	Time	Username	Problem	Language	Result	Execution time	Memory
334381		juggernaut	Chessboard (IZhO18_chessboard)	C++14	70 / 100	253 ms	3564 KiB

chessboard

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
struct Rect{
    ll x,y,x2,y2;
    void _minus(){
        x--,y--,x2--,y2--;
    }
}rect[100005];
ll n,m;
ll solve(ll side){
    ll sz=n/side;
    ll wh=0,bl=side*side*((sz*sz+1)>>1);
    for(ll i=0;i<m;i++){
        ll block_x=rect[i].x/side;
        ll block_y=rect[i].y/side;
        if((block_x+block_y)&1)wh++;
        else bl--;
    }
    return min(wh+bl,n*n-wh-bl);
}
int main(){
    scanf("%lld%lld",&n,&m);
    for(ll i=0;i<m;i++)scanf("%lld%lld%lld%lld",&rect[i].x,&rect[i].y,&rect[i].x2,&rect[i].y2),rect[i]._minus();
    ll res=solve(1);
    for(ll i=2;i*i<=n;i++)if(n%i==0)res=min(res,min(solve(i),solve(n/i)));
    printf("%lld",res);
}

Compilation message (stderr)

chessboard.cpp: In function 'int main()':
chessboard.cpp:23:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |     scanf("%lld%lld",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~
chessboard.cpp:24:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |     for(ll i=0;i<m;i++)scanf("%lld%lld%lld%lld",&rect[i].x,&rect[i].y,&rect[i].x2,&rect[i].y2),rect[i]._minus();
      |                        ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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