Submission #439377

#	Time	Username	Problem	Language	Result	Execution time	Memory
439377		Sorting	Rectangles (IOI19_rect)	C++17	0 / 100	5 ms	3532 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
#pragma GCC optimize("O3")

using namespace std;
typedef long long ll;

const int N = 2500 + 3;

vector<vector<int>> a;
int n, m;
short u[N][N], d[N][N], l[N][N], r[N][N];

struct Min_Segment_Tree{
    static constexpr short DEFAULT_VALUE = SHRT_MAX;
    short t[4 * N];

    int merge(short l, short r){
        return (l < r) ? l : r;
    }

    void init(short arr[], int i = 0, int l = 0, int r = m - 1){
        if(l == r){
            t[i] = arr[l];
            return;
        }
        int mid = (l + r) >> 1;
        init(arr, 2 * i + 1, l, mid);
        init(arr, 2 * i + 2, mid + 1, r);
        t[i] = merge(t[2 * i + 1], t[2 * i + 2]);
    }
    int query(int sl, int sr, int i = 0, int l = 0, int r = m - 1){
        if(sr < l || r < sl) return DEFAULT_VALUE;
        if(sl <=  l && r <= sr) return t[i];
        int mid = (l + r) >> 1;
        return merge(query(sl, sr, 2 * i + 1, l, mid), query(sl, sr, 2 * i + 2, mid + 1, r));
    }
};

struct Min_2D_Segment_Tree{
    static constexpr short DEFAULT_VALUE = SHRT_MAX;
    Min_Segment_Tree t[4 * N];

    int merge(short l, short r){
        return (l < r) ? l : r;
    }

    void merge(Min_Segment_Tree &ret, Min_Segment_Tree &l, Min_Segment_Tree &r){
        for(int i = 0; i < 4 * N; ++i)
            ret.t[i] = merge(l.t[i], r.t[i]);
    }

    void init(short arr[][N], int i = 0, int l = 0, int r = n - 1){
        if(l == r){
            t[i].init(arr[l]);
            return;
        }
        int mid = (l + r) >> 1;
        init(arr, 2 * i + 1, l, mid);
        init(arr, 2 * i + 2, mid + 1, r);
        merge(t[i], t[2 * i + 1], t[2 * i + 2]);
    }
    int query(int sl, int sr, int sl2, int sr2, int i = 0, int l = 0, int r = n - 1){
        //cout << "query " << sl << " " << sr << " " << sl2 << " " << sr2 << " - " << i << " " << l << " " << r << endl; 
        if(sr < l || r < sl) return DEFAULT_VALUE;
        if(sl <=  l && r <= sr) return t[i].query(sl2, sr2);
        int mid = (l + r) >> 1;
        return merge(query(sl, sr, sl2, sr2, 2 * i + 1, l, mid), query(sl, sr, sl2, sr2, 2 * i + 2, mid + 1, r));
    }
};

struct Max_Segment_Tree{
    static constexpr short DEFAULT_VALUE = SHRT_MIN;
    short t[4 * N];

    int merge(short l, short r){
        return (l > r) ? l : r;
    }

    void init(short arr[], int i = 0, int l = 0, int r = m - 1){
        if(l == r){
            t[i] = arr[l];
            return;
        }
        int mid = (l + r) >> 1;
        init(arr, 2 * i + 1, l, mid);
        init(arr, 2 * i + 2, mid + 1, r);
        t[i] = merge(t[2 * i + 1], t[2 * i + 2]);
    }
    int query(int sl, int sr, int i = 0, int l = 0, int r = m - 1){
        if(sr < l || r < sl) return DEFAULT_VALUE;
        if(sl <=  l && r <= sr) return t[i];
        int mid = (l + r) >> 1;
        return merge(query(sl, sr, 2 * i + 1, l, mid), query(sl, sr, 2 * i + 2, mid + 1, r));
    }
};

struct Max_2D_Segment_Tree{
    static constexpr short DEFAULT_VALUE = SHRT_MIN;
    Min_Segment_Tree t[4 * N];

    int merge(short l, short r){
        return (l > r) ? l : r;
    }

    void merge(Min_Segment_Tree &ret, Min_Segment_Tree &l, Min_Segment_Tree &r){
        for(int i = 0; i < 4 * N; ++i)
            ret.t[i] = merge(l.t[i], r.t[i]);
    }

    void init(short arr[][N], int i = 0, int l = 0, int r = n - 1){
        if(l == r){
            t[i].init(arr[l]);
            return;
        }
        int mid = (l + r) >> 1;
        init(arr, 2 * i + 1, l, mid);
        init(arr, 2 * i + 2, mid + 1, r);
        merge(t[i], t[2 * i + 1], t[2 * i + 2]);
    }
    int query(int sl, int sr, int sl2, int sr2, int i = 0, int l = 0, int r = n - 1){
        //cout << "query " << sl << " " << sr << " " << sl2 << " " << sr2 << " - " << i << " " << l << " " << r << endl; 
        if(sr < l || r < sl) return DEFAULT_VALUE;
        if(sl <=  l && r <= sr) return t[i].query(sl2, sr2);
        int mid = (l + r) >> 1;
        return merge(query(sl, sr, sl2, sr2, 2 * i + 1, l, mid), query(sl, sr, sl2, sr2, 2 * i + 2, mid + 1, r));
    }
};

Max_2D_Segment_Tree u_st, l_st;
Min_2D_Segment_Tree d_st, r_st;

void init(){
    stack<int> st;
    for(int j = 0; j < m; ++j){
        for(int i = 0; i < n; ++i){
            while(!st.empty() && a[i][j] > a[st.top()][j]){
                d[st.top()][j] = i;
                st.pop();
            }
            st.push(i);
        }
        while(!st.empty()){
            d[st.top()][j] = n;
            st.pop();
        }
        for(int i = n - 1; i >= 0; --i){
            while(!st.empty() && a[i][j] > a[st.top()][j]){
                u[st.top()][j] = i;
                st.pop();
            }
            st.push(i);
        }
        while(!st.empty()){
            u[st.top()][j] = -1;
            st.pop();
        }
    }

    for(int i = 0; i < n; ++i){
        for(int j = 0; j < m; ++j){
            while(!st.empty() && a[i][j] > a[i][st.top()]){
                r[i][st.top()] = j;
                st.pop();
            }
            st.push(j);
        }
        while(!st.empty()){
            r[i][st.top()] = m;
            st.pop();
        }
        for(int j = m - 1; j >= 0; --j){
            while(!st.empty() && a[i][j] > a[i][st.top()]){
                l[i][st.top()] = j;
                st.pop();
            }
            st.push(j);
        }
        while(!st.empty()){
            l[i][st.top()] = -1;
            st.pop();
        }
    }
}

bool check(int x1, int y1, int x2, int y2){
    return u_st.query(x1, x2, y1, y2) >= x1 - 1 && d_st.query(x1, x2, y1, y2) <= x2 + 1 && l_st.query(x1, x2, y1, y2) >= y1 - 1 && r_st.query(x1, x2, y1, y2) <= y2 + 1; 
}

long long count_rectangles(vector<vector<int>> _a) {
    swap(a, _a);
	n = a.size(), m = a[0].size();

    init();
    u_st.init(u);
    d_st.init(d);
    r_st.init(r);
    l_st.init(l);

    ll ans = 0;
    vector<array<int, 4>> v;
    for(int x = 1; x < n - 1; ++x)
        for(int y = 1; y < m - 1; ++y)
            v.push_back({u[x][y] + 1, l[x][y] + 1, d[x][y] - 1, r[x][y] - 1});
    sort(v.begin(), v.end());
    v.resize(unique(v.begin(), v.end()) - v.begin());

    for(auto [x1, y1, x2, y2]: v){
        if(x1 <= 0 || y1 <= 0 || x2 >= n - 1 || y2 >= m - 1) continue;
        //cout << x1 << " " << y1 << " " << x2 << " " << y2 << endl;
        ans += check(x1, y1, x2, y2); 
    }
    return ans;
}

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