Submission #285452

#	Time	Username	Problem	Language	Result	Execution time	Memory
285452		caoash	Rectangles (IOI19_rect)	C++14	72 / 100	5127 ms	832228 KiB

rect

    #include "rect.h"
    #include <bits/stdc++.h>
    using namespace std;
     
    #define ar array
     
    const int mxN=2.5e3;
    int n, m, l[mxN], r[mxN], ft[mxN+1];
    vector<ar<int, 2>> p[mxN][mxN][2];
     
    void upd(int i, int x) {
    	for(++i; i<=m; i+=i&-i)
    		ft[i]+=x;
    }
     
    int qry(int i) {
    	int r=0;
    	for(; i; i-=i&-i)
    		r+=ft[i];
    	return r;
    }
     
    void gr(vector<vector<int>> &a, int b) {
    	int n=a.size(), m=a[0].size();
    	vector<ar<int, 3>> s;
    	for(int i=0; i<n; ++i) {
    		for(int j=0; j<m; ++j) {
    			l[j]=j-1;
    			while(~l[j]&&a[i][l[j]]<=a[i][j])
    				l[j]=l[l[j]];
    		}
    		for(int j=m-1; ~j; --j) {
    			r[j]=j+1;
    			while(r[j]<m&&a[i][r[j]]<=a[i][j])
    				r[j]=r[r[j]];
    			if(~l[j]&&r[j]<m)
    				s.push_back({l[j]+1, r[j]-1, i});
    		}
    	}
    	sort(s.begin(), s.end());
    	for(int i=0, j; i<s.size(); i=j+1) {
    		for(j=i; j+1<s.size()&&s[j+1][0]==s[i][0]&&s[j+1][1]==s[i][1]&&s[j+1][2]<=s[j][2]+1; ++j);
    		int l1=s[i][0], r1=s[i][1], l2=s[i][2], r2=s[j][2], x2=r2, y2=r1;
    		if(b)
    			swap(x2, y2);
    		for(int k=l2; k<=r2; ++k) {
    			int x=k, y=l1;
    			if(b)
    				swap(x, y);
    			p[x][y][b].push_back({-x2, y2});
    		}
    	}
    }
     
    long long count_rectangles(vector<vector<int>> a) {
    	n=a.size();
    	m=a[0].size();
    	vector<vector<int>> b(m, vector<int>(n));
    	for(int i=0; i<n; ++i)
    		for(int j=0; j<m; ++j)
    			b[j][i]=a[i][j];
    	gr(a, 0);
    	gr(b, 1);
    	int ans=0;
    	for(int i=1; i<n-1; ++i) {
    		for(int j=1; j<m-1; ++j) {
    			for(int k : {0, 1})
    				sort(p[i][j][k].begin(), p[i][j][k].end());
    			int d=0;
    			for(int c=0; c<p[i][j][1].size(); ++c) {
    				while(d<p[i][j][0].size()&&p[i][j][0][d]<=p[i][j][1][c])
    					upd(p[i][j][0][d++][1], 1);
    				ans+=qry(p[i][j][1][c][1]+1);
    			}
    			while(d)
    				upd(p[i][j][0][--d][1], -1);
    		}
    	}
    	return ans;
    }

Compilation message (stderr)

rect.cpp: In function 'void gr(std::vector<std::vector<int> >&, int)':
rect.cpp:41:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |      for(int i=0, j; i<s.size(); i=j+1) {
      |                      ~^~~~~~~~~
rect.cpp:42:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |       for(j=i; j+1<s.size()&&s[j+1][0]==s[i][0]&&s[j+1][1]==s[i][1]&&s[j+1][2]<=s[j][2]+1; ++j);
      |                ~~~^~~~~~~~~
rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:70:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |        for(int c=0; c<p[i][j][1].size(); ++c) {
      |                     ~^~~~~~~~~~~~~~~~~~
rect.cpp:71:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |         while(d<p[i][j][0].size()&&p[i][j][0][d]<=p[i][j][1][c])
      |               ~^~~~~~~~~~~~~~~~~~

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