Submission #168425

#	Time	Username	Problem	Language	Result	Execution time	Memory
168425		juggernaut	Chessboard (IZhO18_chessboard)	C++14	39 / 100	661 ms	4476 KiB

chessboard

#include<bits/stdc++.h>
#define int long long int
#define fr first
#define sc second
using namespace std;
int n,k,i,j,x,y,res;
pair<int,int>p[100001];
bool a[1001][1001];
int get(int f,int q){
    int cnt=0;
    for(int i=0;i<n;i++)
    for(int j=0;j<n;j++){
        x=i/f;
        y=j/f;
        if(q){
            if((x+y)%2==0){
                if(a[i][j])cnt++;
            }else{
                if(!a[i][j])cnt++;
            }
        }else{
            if((x+y)%2==0){
                if(!a[i][j])cnt++;
            }else{
                if(a[i][j])cnt++;
            }
        }
    }
    return cnt;
}
int get(int f){
    return min(get(f,0),get(f,1));
}
main(){
    scanf("%lld%lld",&n,&k);
    for(i=0;i<k;i++){
        scanf("%lld%lld%lld%lld",&p[i].fr,&p[i].sc,&p[i].fr,&p[i].sc);
        p[i].fr--;
        p[i].sc--;
        a[p[i].fr][p[i].sc]=1;
    }
    res=get(1);
    for(j=2;j*j<=n;j++){
        if(n%j==0){
            res=min(res,get(j));
            res=min(res,get(n/j));
        }
    }
    printf("%lld",res);
}

Compilation message (stderr)

chessboard.cpp:34:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
chessboard.cpp: In function 'int main()':
chessboard.cpp:35:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld%lld",&n,&k);
     ~~~~~^~~~~~~~~~~~~~~~~~
chessboard.cpp:37:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld%lld%lld%lld",&p[i].fr,&p[i].sc,&p[i].fr,&p[i].sc);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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