Submission #348049

#	Time	Username	Problem	Language	Result	Execution time	Memory
348049		juggernaut	Rectangles (IOI19_rect)	C++14	50 / 100	3609 ms	98540 KiB

rect

#include"rect.h"
#include<bits/stdc++.h>
#ifdef EVAL
#else
#include"grader.cpp"
#endif
using namespace std;
int b[2505][2505],n,m;
vector<vector<int>>a;
bool check(int r1,int c1,int r2,int c2){
	for(int i=r1;i<=r2;i++)
		for(int j=c1;j<=c2;j++)
			if(a[i][j]>=min(min(a[i][c1-1],a[i][c2+1]),min(a[r1-1][j],a[r2+1][j])))return 0;
	return 1;
}
int get(int x,int y,int x2,int y2){
    int sum=b[x2][y2];
    if(x&&y)sum+=b[x-1][y-1];
    if(x)sum-=b[x-1][y2];
    if(y)sum-=b[x2][y-1];
    return sum;
}
long long count_rectangles(vector<vector<int>>a){
	n=a.size(),m=a[0].size();
	::a=a;
	long long res=0;
	if((n<=200&&m<=200)||(n<=3)){
        for(int i=1;i<n-1;i++)
		for(int j=1;j<m-1;j++)
			for(int I=i;I<n-1;I++)
				for(int J=j;J<m-1;J++)res+=check(i,j,I,J);
	}else{
	    for(int i=0;i<n;i++)
        for(int j=0;j<m;j++){
            b[i][j]=a[i][j];
            if(i&&j)b[i][j]-=b[i-1][j-1];
            if(i)b[i][j]+=b[i-1][j];
            if(j)b[i][j]+=b[i][j-1];
        }
        for(int i=1;i+1<n;i++)
        for(int j=1;j+1<m;j++)
            if(!a[i][j]&&a[i][j-1]&&a[i-1][j]){
                int x=i;
                while(x+1<n&&!a[x+1][j])x++;
                int y=j;
                while(y+1<m&&!a[i][y+1])y++;
                if(get(i,j,x,y)==0&&get(i-1,j,i-1,y)==y-j+1&&get(x+1,j,x+1,y)==y-j+1&&get(i,j-1,x,j-1)==x-i+1&&get(i,y+1,x,y+1)==x-i+1)res++;
            }
	}
    return res;
}

• Subtask 1: 8 / 8
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 0 / 22
• Subtask 5: 10 / 10
• Subtask 6: 13 / 13
• Subtask 7: 0 / 28