Submission #1084472

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084472		steveonalex	Rectangles (IOI19_rect)	C++17	72 / 100	1407 ms	1048576 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }


namespace Sub7{
    vector<array<short, 3>> generate_pair(vector<vector<int>> a){
        int n = a.size(), m = a[0].size();
        vector<array<short, 3>> what;
        for(int i = 1; i+1<n; ++i){
            vector<int> st; st.reserve(m);
            for(int j = m-1; j>=0; --j){
                int best = -1;
                while(st.size() && a[i][st.back()] <= a[i][j]){
                    int r = st.back();
                    maximize(best, a[i][r]);
                    if (r != j + 1) what.push_back({{i, j, r}});
                    st.pop_back();
                }
                if (st.size() && best < a[i][j] && st.back() != j + 1){
                    what.push_back({{i, j, st.back()}});
                }
                st.push_back(j);
            }
            // sort(ALL(what[i]));
        }
        return what;
    }

    ll solve(vector<vector<int>> a){
        int n, m;
        n = a.size(), m = a[0].size();
        ll ans = 0;

        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];

        vector<array<short, 3>> pair_row = generate_pair(a), pair_col = generate_pair(b);

        if (pair_row.size() + pair_col.size() >= 1e7) return 0;
        
        vector<short> candidate_row[n][m], candidate_col[n][m];
        vector<short> idx_col[n][n], idx_row[m][m];
        for(array<short, 3> j: pair_row){
            int i = j[0];
            candidate_row[i][j[1] + 1].push_back(j[2] - 1);
            idx_row[j[1]][j[2]].push_back(i);
        }

        for(array<short, 3> i: pair_col){
            int j = i[0];
            candidate_col[i[1] + 1][j].push_back(i[2] - 1);
            idx_col[i[1]][i[2]].push_back(j);
        }

        for(int i = 1; i+1<n; ++i)
        for(int j = 1; j+1<m; ++j) if (candidate_row[i][j].size() && candidate_col[i][j].size()){
            for(short y: candidate_row[i][j]) for(short x: candidate_col[i][j]){
                // check the rectangle (i, j, x, y)
                // printArr(idx_row[j-1][y+1]);
                int cnt1 = upper_bound(ALL(idx_row[j-1][y+1]), x) - lower_bound(ALL(idx_row[j-1][y+1]), i);
                if (cnt1 != x - i + 1) continue;
                int cnt2 = upper_bound(ALL(idx_col[i-1][x+1]), y) - lower_bound(ALL(idx_col[i-1][x+1]), j);
                if (cnt2 != y - j + 1) continue;
                ans++;
            }
        }

        





        return ans;
    }
}

ll count_rectangles(vector<vector<int>> a) {
    return Sub7::solve(a);
    
}

Compilation message (stderr)

rect.cpp: In function 'std::vector<std::array<short int, 3> > Sub7::generate_pair(std::vector<std::vector<int> >)':
rect.cpp:68:54: warning: narrowing conversion of 'i' from 'int' to 'short int' [-Wnarrowing]
   68 |                     if (r != j + 1) what.push_back({{i, j, r}});
      |                                                      ^
rect.cpp:68:57: warning: narrowing conversion of 'j' from 'int' to 'short int' [-Wnarrowing]
   68 |                     if (r != j + 1) what.push_back({{i, j, r}});
      |                                                         ^
rect.cpp:68:60: warning: narrowing conversion of 'r' from 'int' to 'short int' [-Wnarrowing]
   68 |                     if (r != j + 1) what.push_back({{i, j, r}});
      |                                                            ^
rect.cpp:72:38: warning: narrowing conversion of 'i' from 'int' to 'short int' [-Wnarrowing]
   72 |                     what.push_back({{i, j, st.back()}});
      |                                      ^
rect.cpp:72:41: warning: narrowing conversion of 'j' from 'int' to 'short int' [-Wnarrowing]
   72 |                     what.push_back({{i, j, st.back()}});
      |                                         ^
rect.cpp:72:51: warning: narrowing conversion of 'st.std::vector<int>::back()' from '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} to 'short int' [-Wnarrowing]
   72 |                     what.push_back({{i, j, st.back()}});
      |                                            ~~~~~~~^~

• 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