Submission #1241830

#	Time	Username	Problem	Language	Result	Execution time	Memory
1241830		Zbyszek99	Rectangles (IOI19_rect)	C++20	100 / 100	2986 ms	783384 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define vi vector<int>
#define vl vector<long long>
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

const int tree_siz = 1024*8-1;
int sum[tree_siz+1];

int get_sum(int akt, int p1, int p2, int s1, int s2)
{
	if(p2 < s1 || p1 > s2) return 0;
	if(p1 >= s1 && p2 <= s2) return sum[akt];
	return get_sum(akt*2,p1,(p1+p2)/2,s1,s2)+get_sum(akt*2+1,(p1+p2)/2+1,p2,s1,s2);
}

void upd(int v)
{
	sum[v] = sum[v*2]+sum[v*2+1];
	if(v != 1) upd(v/2);
}

void change(int ind, int x)
{
	sum[tree_siz/2+ind+1] += x;
	upd((tree_siz/2+1+ind)/2);
}

vector<pair<short,short>> X_segs[2501][2501];
vector<pair<short,short>> Y_segs[2501][2501];

vector<pair<short,short>> count_regions(vi& x)
{
	vector<pair<short,short>> ans;
	stack<int> st;
	rep(i,siz(x))
	{
		while(!st.empty() && x[st.top()] < x[i]) st.pop();
		if(i != 0 && siz(st) != 0)
		{
			int end_ = st.top()+1;
			if(end_ <= i-1)
			{
				ans.pb({end_,i-1});
			}
		}
		st.push(i);
	}
	while(!st.empty()) st.pop();
	for(int i = siz(x)-1; i >= 0; i--)
	{
		while(!st.empty() && x[st.top()] < x[i]) st.pop();
		if(i != siz(x)-1 && siz(st) != 0)
		{
			int end_ = st.top()-1;
			if(end_ >= i+1)
			{
				ans.pb({i+1,end_});
			}
		}
		st.push(i);
	}
	sort(all(ans));
	vector<pair<short,short>> ans2;
	pii pop = {-1,-1};
	forall(it,ans)
	{
		if(it.ff == pop.ff && it.ss == pop.ss) continue;
		ans2.pb(it);
		pop = it;
	}
	return ans2;
}

int first_poz[2501][2501];
int last_poz[2501][2501];

ll count_rectangles(vector<vi> arr) 
{
	int n = siz(arr);
	int m = siz(arr[0]);
	vector<pair<short,short>> segs;
	for(int i = n-2; i >= 1; i--)
	{
		segs = count_regions(arr[i]);
		forall(it,segs)
		{
			int last_iter = i;
			if(first_poz[it.ff][it.ss] == i+1) last_iter = last_poz[it.ff][it.ss];
			else
			{
				last_poz[it.ff][it.ss] = i;
			}
			first_poz[it.ff][it.ss] = i;
			Y_segs[i][it.ff].pb({last_iter,it.ss});
		}
	}
	rep(i,2501) rep(j,2501)
	{
		last_poz[i][j] = 0;
		first_poz[i][j] = 0;
	}
	vi arr2(n);
	for(int j = m-2; j >= 1; j--)
	{
		rep(i,n) arr2[i] = arr[i][j];
		segs = count_regions(arr2);
		forall(it,segs)
		{
			int last_iter = j;
			if(first_poz[it.ff][it.ss] == j+1) last_iter = last_poz[it.ff][it.ss];
			else
			{
				last_poz[it.ff][it.ss] = j;
			}
			first_poz[it.ff][it.ss] = j;
			X_segs[it.ff][j].pb({it.ss,last_iter});
		}
	}
	ll ans = 0;
	rep2(i,1,n-2)
	{
		rep2(j,1,m-2)
		{
			sort(all(X_segs[i][j]));
			sort(all(Y_segs[i][j]));
			reverse(all(Y_segs[i][j]));
			int cur_Y = siz(Y_segs[i][j])-1;
			forall(it,Y_segs[i][j])
			{
				change(it.ss,1);
			}
			forall(it,X_segs[i][j])
			{
				while(cur_Y >= 0 && Y_segs[i][j][cur_Y].ff < it.ff)
				{
					change(Y_segs[i][j][cur_Y].ss,-1);
					cur_Y--;
				}
				ans += get_sum(1,0,tree_siz/2,0,it.ss);
			}
			rep(k,cur_Y+1)
			{
				change(Y_segs[i][j][k].ss,-1);
			}
		}
	}
	return ans;
}

• 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