Submission #405746

#	Time	Username	Problem	Language	Result	Execution time	Memory
405746		rocks03	Rectangles (IOI19_rect)	C++14	50 / 100	5075 ms	548324 KiB

rect

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
#define debug(x) cout << #x << ": " << x << " "
#define nl cout << "\n"
#define rep(i, a, b) for(int i = (a); i <= (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

long long count_rectangles(vector<vector<int>> a){
    int N = SZ(a), M = SZ(a[0]);
    map<pair<pii, pii>, int> mp;
    vector<int> rt[N][M], dw[N][M];
    rep(i, 0, N - 1){
        vector<int> st;
        per(j, M - 1, 0){
            while(!st.empty() && a[i][j] > a[i][st.back()]){
                if(j + 1 < st.back()) rt[i][j].pb(st.back());
                st.pop_back();
            }
            if(!st.empty() && j + 1 < st.back()) rt[i][j].pb(st.back());
            if(!st.empty() && a[i][j] == a[i][st.back()]) st.pop_back();
            st.pb(j);
        }
    }
    rep(j, 0, M - 1){
        vector<int> st;
        per(i, N - 1, 0){
            while(!st.empty() && a[i][j] > a[st.back()][j]){
                if(i + 1 < st.back()) dw[i][j].pb(st.back());
                st.pop_back();
            }
            if(!st.empty() && i + 1 < st.back()) dw[i][j].pb(st.back());
            if(!st.empty() && a[i][j] == a[st.back()][j]) st.pop_back();
            st.pb(i);
        }
    }
    ll ans = 0;
    rep(i, 0, N - 1){
        rep(j, 0, M - 1){
            for(int j2 : rt[i][j]){
                mp[{{i, i}, {j, j2}}] = 1;
            }
        }
    }
    rep(i, 1, N - 2){
        rep(j, 0, M - 1){
            for(int j2 : rt[i][j]){
                set<int> st;
                for(int i2 : dw[i - 1][j + 1]) st.insert(i2);
                rep(k, j + 2, j2 - 1){
                    set<int> st2;
                    for(int i2 : dw[i - 1][k]){
                        if(st.count(i2)) st2.insert(i2);
                    }
                    st = st2;
                }
                for(int i2 : st){
                    bool ok = true;
                    rep(k, i, i2 - 1){
                        if(!mp.count({{k, k}, {j, j2}})){
                            ok = false; break;
                        }
                    }
                    ans += (ok == true);
                }
            }
        }
    }
    return ans;
}

• 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