Submission #725127

#	Time	Username	Problem	Language	Result	Execution time	Memory
725127		QwertyPi	Rectangles (IOI19_rect)	C++14	72 / 100	4214 ms	687336 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")
#define fi first
#define se second
#define pii pair<int, int>
using namespace std;
const int N = 2500 + 11;
 
struct DSU{
	int dsu[N], l[N], r[N];
	void init(int n){
		for(int i = 0; i <= n + 2; i++) dsu[i] = l[i] = r[i] = i;
	}
	int root(int x){
		if(x == dsu[x]) return x;
		return dsu[x] = root(dsu[x]);
	}
	void join(int x, int y){
		x = root(x), y = root(y);
		if(x == y) return;
		dsu[y] = x;
		l[x] = min(l[x], l[y]);
		r[x] = max(r[x], r[y]);
	}
} dsu;
 
int at(const vector<int>& v, int idx){
	if(idx < 0 || idx >= (int) v.size()) return -(1 << 30);
	return v[idx];
}
 
vector<pii> build(const vector<int>& v){
	vector<pii> res;
	vector<pii> vp; int n = v.size();
	for(int i = 0; i < n; i++){
		vp.push_back({v[i], i});
	}
	sort(vp.begin(), vp.end());
	dsu.init(n);
	for(auto i : vp){
		dsu.join(i.se, i.se + 1);
		int rt = dsu.root(i.se);
		int b_l = dsu.l[rt], b_r = dsu.r[rt] - 1;
		if(at(v, b_l - 1) > i.fi && at(v, b_r + 1) > i.fi){
			res.push_back({b_l, b_r});
		}
	}
	return res;
}
 
 
struct Rect{
	int16_t x1, x2, y1, y2;
	void pr() { printf("%d %d %d %d\n", x1, x2, y1, y2); }
	friend Rect operator+ (const Rect& a, const Rect& b){
		return {max(a.x1, b.x1), min(a.x2, b.x2), max(a.y1, b.y1), min(a.y2, b.y2)};
	}
};
 
void split(const vector<Rect>& a, vector<Rect>& al, vector<Rect>& ar, int xm){
    for(auto r : a) {
        if(r.x1 <= xm) al.push_back(r);
        else ar.push_back(r);
    }
}
 
long long ans = 0;
 
struct BIT2D{
    int bit[N][N];
    void add(int x, int y, int v){
        x++; y++;
        for(int i = x; i < N; i += i & -i){
            for(int j = y; j < N; j += j & -j){
                bit[i][j] += v;
            }
        }
    }
    void qry(int x, int y){
        x++; y++;
        for(int i = x; i; i -= i & -i){
            for(int j = y; j; j -= j & -j){
                ans += bit[i][j];
            }
        }
    }
} bit2;
 
void calc(const vector<Rect>& ad, const vector<Rect>& qr){
    int l = 0, r = 0;
    while(l + r < (int) ad.size() + (int) qr.size()){
        if(r == (int) qr.size() || (l != (int) ad.size() && ad[l].x2 <= qr[r].x2)){
            bit2.add(ad[l].y1, ad[l].y2, 1); l++;
        }else{
            bit2.qry(qr[r].y1, qr[r].y2); r++;
        }
    }
    for(int l = 0; l < (int) ad.size(); l++){
        bit2.add(ad[l].y1, ad[l].y2, -1);
    }
}
 
void solve(int xl, int xr, vector<Rect>& A, vector<Rect>& B) {
    if(xl == xr){
        calc(A, B);
    }else{
        int xm = (xl + xr) / 2;
        vector<Rect> AL, AR, BL, BR; split(A, AL, AR, xm), split(B, BL, BR, xm);
        solve(xl, xm, AL, BL), solve(xm + 1, xr, AR, BR), calc(AL, BR);
    }
}
 
vector<int> xs[N * N], ys[N * N];
vector<Rect> xr, yr;
vector<pii> x[N], y[N];

void counting_sort(vector<Rect>& a){
	vector<Rect> v[N];
	for(auto& r : a) v[r.x2].push_back(r);
	a.clear();
	for(int i = 0; i < N; i++){
		for(auto& r : v[i]) a.push_back(r);
	}
}

long long count_rectangles(std::vector<std::vector<int>> a) {
	int n = a.size(), m = a[0].size(), mx = 0;
	for(int i = 0; i < n; i++) for(int j = 0; j < m; j++) mx = max(mx, a[i][j]);
	for(int i = 0; i < n; i++){
		vector<int> v; for(int j = 0; j < m; j++) v.push_back(a[i][j]);
		x[i] = build(v);
		for(pii p : x[i]){
			xs[p.fi * m + p.se].push_back(i);
		}
	}
	for(int i = 0; i < m * m; i++){
		int x1 = i / m, x2 = i % m; if(x1 > x2) continue;
		int y1 = -2, y2 = -2;
		for(auto j : xs[i]){
			if(j == y2 + 1){
				y2++;
			}else{
				if(y1 != -2) xr.push_back({x1, x2, y1, y2});
				y1 = y2 = j;
			}
		}
		if(y1 != -2) xr.push_back({x1, x2, y1, y2});
	}
	for(int j = 0; j < m; j++){
		vector<int> v; for(int i = 0; i < n; i++) v.push_back(a[i][j]);
		y[j] = build(v);
		for(pii p : y[j]){
			ys[p.fi * n + p.se].push_back(j);
		}
	}
	for(int i = 0; i < n * n; i++){
		int y1 = i / n, y2 = i % n; if(y1 > y2) continue;
		int x1 = -2, x2 = -2;
		for(auto j : ys[i]){
			if(j == x2 + 1){
				x2++;
			}else{
				if(x1 != -2) yr.push_back({x1, x2, y1, y2});
				x1 = x2 = j;
			}
		}
		if(x1 != -2) yr.push_back({x1, x2, y1, y2});
	}
	for(auto& r1 : xr) r1.x1 = m - 1 - r1.x1, r1.y2 = n - 1 - r1.y2;
	for(auto& r2 : yr) r2.x1 = m - 1 - r2.x1, r2.y2 = n - 1 - r2.y2;

	counting_sort(xr); counting_sort(yr); 
	if(n <= 1000 || mx <= 1) solve(0, m - 1, xr, yr);
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:145:32: warning: narrowing conversion of 'x1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  145 |     if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                ^~
rect.cpp:145:36: warning: narrowing conversion of 'x2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  145 |     if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                    ^~
rect.cpp:145:40: warning: narrowing conversion of 'y1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  145 |     if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                        ^~
rect.cpp:145:44: warning: narrowing conversion of 'y2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  145 |     if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                            ^~
rect.cpp:149:30: warning: narrowing conversion of 'x1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  149 |   if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                              ^~
rect.cpp:149:34: warning: narrowing conversion of 'x2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  149 |   if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                  ^~
rect.cpp:149:38: warning: narrowing conversion of 'y1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  149 |   if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                      ^~
rect.cpp:149:42: warning: narrowing conversion of 'y2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  149 |   if(y1 != -2) xr.push_back({x1, x2, y1, y2});
      |                                          ^~
rect.cpp:165:32: warning: narrowing conversion of 'x1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  165 |     if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                ^~
rect.cpp:165:36: warning: narrowing conversion of 'x2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  165 |     if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                    ^~
rect.cpp:165:40: warning: narrowing conversion of 'y1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  165 |     if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                        ^~
rect.cpp:165:44: warning: narrowing conversion of 'y2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  165 |     if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                            ^~
rect.cpp:169:30: warning: narrowing conversion of 'x1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  169 |   if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                              ^~
rect.cpp:169:34: warning: narrowing conversion of 'x2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  169 |   if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                  ^~
rect.cpp:169:38: warning: narrowing conversion of 'y1' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  169 |   if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                      ^~
rect.cpp:169:42: warning: narrowing conversion of 'y2' from 'int' to 'int16_t' {aka 'short int'} [-Wnarrowing]
  169 |   if(x1 != -2) yr.push_back({x1, x2, y1, y2});
      |                                          ^~

• 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