Submission #296588

#	Time	Username	Problem	Language	Result	Execution time	Memory
296588		Osama_Alkhodairy	Rectangles (IOI19_rect)	C++17	50 / 100	5043 ms	298416 KiB

rect

#include <bits/stdc++.h>
#include "rect.h"
//~ #include "grader.cpp"
using namespace std;
#define ll long long

int n, m;
vector <vector <int> > a;
set <pair <pair <int, int>, pair <int, int> > > vis;

vector <int> calc(vector <int> &a, int b, int c){
    //~ b = 0 for >
    //~ b = 1 for >=
    //~ c = 0 for forward
    //~ c = 1 for backward
    int n = a.size();
    vector <int> inds;
    for(int i = 0 ; i < n ; i++){
        if(c == 0) inds.push_back(i);
        else inds.push_back(n - i - 1);
    }
    vector <int> ret(n);
    vector <int> cur;
    for(auto &i : inds){
        while(cur.size() && a[i] >= a[cur.back()] + b){
            cur.pop_back();
        }
        if(cur.size() == 0) ret[i] = -1;
        else ret[i] = cur.back();
        cur.push_back(i);
    }
    return ret;
}
bool check(int r1, int c1, int r2, int c2){
    if(r1 == -1 || c1 == -1 || r2 == -1 || c2 == -1) return 0;
    if(vis.count(make_pair(make_pair(r1, c1), make_pair(r2, c2)))) return 0;
    for(int i = r1 + 1 ; i < r2 ; i++){
        for(int j = c1 + 1 ; j < c2 ; j++){
            if(!(a[r1][j] > a[i][j] && a[r2][j] > a[i][j] && a[i][c1] > a[i][j] && a[i][c2] > a[i][j])){
                return 0;
            }
        }
    }
    vis.insert(make_pair(make_pair(r1, c1), make_pair(r2, c2)));
    return 1;
}
long long count_rectangles(std::vector<std::vector<int> > A) {
    a = A;
    n = a.size();
    m = a[0].size();
    vector <vector <int> > us(n, vector <int>(m)), rs(n, vector <int>(m)), ds(n, vector <int>(m)), ls(n, vector <int>(m));
    vector <vector <int> > ue(n, vector <int>(m)), re(n, vector <int>(m)), de(n, vector <int>(m)), le(n, vector <int>(m));
    for(int i = 0 ; i < n ; i++){
        vector <int> cur = a[i];
        ls[i] = calc(cur, 0, 0);
        le[i] = calc(cur, 1, 0);
        rs[i] = calc(cur, 0, 1);
        re[i] = calc(cur, 1, 1);
    }
    for(int j = 0 ; j < m ; j++){
        vector <int> cur(n);
        for(int i = 0 ; i < n ; i++){
            cur[i] = a[i][j];
        }
        vector <int> g;
        g = calc(cur, 0, 0);
        for(int i = 0 ; i < n ; i++){
            us[i][j] = g[i];
        }
        g = calc(cur, 1, 0);
        for(int i = 0 ; i < n ; i++){
            ue[i][j] = g[i];
        }
        g = calc(cur, 0, 1);
        for(int i = 0 ; i < n ; i++){
            ds[i][j] = g[i];
        }
        g = calc(cur, 1, 1);
        for(int i = 0 ; i < n ; i++){
            de[i][j] = g[i];
        }
    }
    int ret = 0;
    for(int i = 0 ; i < n ; i++){
        for(int j = 0 ; j < m ; j++){
            ret += check(us[i][j], ls[i][j], ds[i][j], rs[i][j]);
        }
    }
    return ret;
}

• 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