Submission #168541

#	Time	Username	Problem	Language	Result	Execution time	Memory
168541		juggernaut	Chessboard (IZhO18_chessboard)	C++14	70 / 100	815 ms	5880 KiB

chessboard

//Just try and the idea will come!
#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],s[100001];
int get(int x1,int y1,int x2,int y2){
    if(x1>x2||y1>y2)return 0;
    int res=(x2-x1+1)*((y2-y1+1)/2);
    if((y2-y1+1)&1){
        res+=(x2-x1+1)/2;
        if((x1+y1)%2==0&&(x2-x1+1)%2==1)res++;
    }
    return res;
}
int get_x(int x1,int y1,int x2,int y2,int f){
    if(x1>x2||y1>y2)return 0;
    int res,x,xx;
    x=(x1+f-1)/f;
    xx=(x2-f+1)/f;
    res=get(x,y1/f,xx,y1/f)*(y2-y1+1);
    if((x1+y1)%2==0)res+=max(0ll,(x*f-1-x1+1))*(y2-y1+1);
    if((x2+y2)%2==0)res+=max(0ll,(x2-xx*f))*(y2-y1+1);
    return res;
}
int get_y(int x1,int y1,int x2,int y2,int f){
    if(x1>x2||y1>y2)return 0;
    int res,x,yy;
    y=(y1+f-1)/f;
    yy=(y2-f+1)/f;
    res=get(x/f,y,x/f,yy)*(x2-x1+1);
    if((x1+y1)%2==0)res+=max(0ll,(y*f-1-y1+1))*(x2-x1+1);
    if((x2+y2)%2==0)res+=max(0ll,(y2-yy*f))*(x2-x1+1);
    return res;
}
int count_white(int x1,int y1,int x2,int y2,int f){
    int x,y,xx,yy,res;
    x=(x1+f-1)/f;
    y=(y1+f-1)/f;
    xx=(x2-f+1)/f;
    yy=(y2-f+1)/f;
    res=f*f*get(x,y,xx,yy);
    res+=get_x(x1,y1,x2,y-1,f)+get_x(x1,yy+1,x2,y2,f);
    res+=get_y(x1,y,x-1,yy,f)+get_y(xx+1,y,x2,yy,f);
    return res;
}
int get(int f){
    int cnt=0,c[2],x;
    c[0]=c[1]=0;
    for(int i=0;i<k;i++){
        x=get(s[i].fr/f,s[i].sc/f,p[i].fr/f,p[i].sc/f);
        c[0]+=x;
        c[1]+=(p[i].fr-s[i].fr+1)*(p[i].sc-s[i].sc+1)-x;
    }
    int m=n/f;
    int res=f*f*((m/2)*m+((m%2)*(m/2)))-c[1]+c[0];
    res=min(res,f*f*((m/2)*m+((m%2)*((m+1)/2)))-c[0]+c[1]);
    return res;
}
main(){
    scanf("%lld%lld",&n,&k);
    for(i=0;i<k;i++){
        scanf("%lld%lld%lld%lld",&s[i].fr,&s[i].sc,&p[i].fr,&p[i].sc);
        p[i].fr--;
        p[i].sc--;
        s[i].fr--;
        s[i].sc--;
    }
    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: In function 'long long int get(long long int)':
chessboard.cpp:50:9: warning: unused variable 'cnt' [-Wunused-variable]
     int cnt=0,c[2],x;
         ^~~
chessboard.cpp: At global scope:
chessboard.cpp:62:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
chessboard.cpp: In function 'int main()':
chessboard.cpp:63:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld%lld",&n,&k);
     ~~~~~^~~~~~~~~~~~~~~~~~
chessboard.cpp:65:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld%lld%lld%lld",&s[i].fr,&s[i].sc,&p[i].fr,&p[i].sc);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
chessboard.cpp: In function 'long long int get_y(long long int, long long int, long long int, long long int, long long int)':
chessboard.cpp:33:12: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
     res=get(x/f,y,x/f,yy)*(x2-x1+1);
         ~~~^~~~~~~~~~~~~~

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