Submission #1084708

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084708		steveonalex	Rectangles (IOI19_rect)	C++17	100 / 100	2994 ms	1026400 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, r, j}});
                    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);
 
        const int N = pair_row.size() + pair_col.size();
        
        vector<short> candidate_row[n][m], candidate_col[n][m];
        int l_col[n][n], r_col[n][n], l_row[m][m], r_row[m][m];
        memset(l_col, 0, sizeof l_col);
        memset(r_col, 0, sizeof r_col);
        memset(l_row, 0, sizeof l_row);
        memset(r_row, 0, sizeof r_row);
        short tape[N];
        for(auto &j: pair_row){
            int i = j[0];
            if (j[1] <= j[2]){
                candidate_row[i][j[1] + 1].push_back(j[2] - 1);
            }
            else{
                candidate_row[i][j[1] - 1].push_back(j[2] + 1);
                swap(j[1], j[2]);
            }
            l_row[j[1]][j[2]]++;
        }
 
        // block_of_code{
        //     // check
        //     bool check = true;
        //     for(int i = 0; i < n; ++i) for(int j: a[i]) if (j > 1) check = false;
        //     if (check == false && min(n, m) >= 2000) return 0;
        // }
 
        for(auto &i: pair_col){
            int j = i[0];
          	if (i[1] >= i[2]) swap(i[1], i[2]);
            candidate_col[i[1] + 1][j].push_back(i[2] - 1);
            l_col[i[1]][i[2]]++;
        }
 
 
        int sum = 0;
        for(int i = 0; i<n; ++i) for(int j = i; j<n; ++j) {
            r_col[i][j] = sum;
            sum += l_col[i][j];
            l_col[i][j] = r_col[i][j];
        }
 
        for(int i = 0; i<m; ++i) for(int j = i; j<m; ++j) {
            r_row[i][j] = sum;
            sum += l_row[i][j];
            l_row[i][j] = r_row[i][j];
        }
 
        for(array<short, 3> j: pair_row){
            int i = j[0];
            tape[r_row[j[1]][j[2]]++] = i;
        }
        for(array<short, 3> i: pair_col){
            int j = i[0];
            tape[r_col[i[1]][i[2]]++] = 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 _j: candidate_row[i][j]) for(short _i: candidate_col[i][j]){
                // check the rectangle (i, j, x, y)
                // printArr(idx_row[j-1][y+1]);
                int u = i, v = j, x = _i, y = _j;
                if (u >= x) swap(u, x);
                if (v >= y) swap(v, y);
                #define get1(x, y) tape + l_row[x][y], tape + r_row[x][y]
                #define get2(x, y) tape + l_col[x][y], tape + r_col[x][y]
                int cnt1 = upper_bound(get1(v-1, y+1), x) - lower_bound(get1(v-1, y+1), u);
                if (cnt1 != x - u + 1) continue;
                int cnt2 = upper_bound(get2(u-1, x+1), y) - lower_bound(get2(u-1, x+1), v);
                if (cnt2 != y - v + 1) continue;
                ans++;
            }
        }
        return ans;
    }
}
 
ll count_rectangles(vector<vector<int>> a) {
    return Sub7::solve(a);
    
}
 
 
// int main(void){
//     ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
//     clock_t start = clock();
 
//     int n,m; cin >> n >> m;
//     vector<vector<int>> a(n, vector<int>(m));
//     for(int i = 0; i<n; ++i) for(int j = 0; j<m; ++j) cin >> a[i][j];
 
//     cout << count_rectangles(a) << "\n";
 
//     cerr << "Time elapsed: " << clock() - start << " ms\n";
//     return 0;
// }

Compilation message (stderr)

rect.cpp: In function 'std::vector<std::array<short int, 3> > Sub7::generate_pair(std::vector<std::vector<int> >)':
rect.cpp:69:54: warning: narrowing conversion of 'i' from 'int' to 'short int' [-Wnarrowing]
   69 |                     if (r != j + 1) what.push_back({{i, r, j}});
      |                                                      ^
rect.cpp:69:57: warning: narrowing conversion of 'r' from 'int' to 'short int' [-Wnarrowing]
   69 |                     if (r != j + 1) what.push_back({{i, r, j}});
      |                                                         ^
rect.cpp:69:60: warning: narrowing conversion of 'j' from 'int' to 'short int' [-Wnarrowing]
   69 |                     if (r != j + 1) what.push_back({{i, r, j}});
      |                                                            ^
rect.cpp:73:38: warning: narrowing conversion of 'i' from 'int' to 'short int' [-Wnarrowing]
   73 |                     what.push_back({{i, j, st.back()}});
      |                                      ^
rect.cpp:73:41: warning: narrowing conversion of 'j' from 'int' to 'short int' [-Wnarrowing]
   73 |                     what.push_back({{i, j, st.back()}});
      |                                         ^
rect.cpp:73:51: 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]
   73 |                     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: 28 / 28