Submission #419213

#	Time	Username	Problem	Language	Result	Execution time	Memory
419213		peuch	Seats (IOI18_seats)	C++17	31 / 100	4058 ms	72708 KiB

seats

#include <bits/stdc++.h>
#include "seats.h"
 
#define ff first
#define ss second
 
using namespace std;
 
typedef pair<int, int> pii;
 
const int maxn = 1e3+10;
 
int n, m;
 
vector<int> x, y;
 
struct Node
{
	int mn_x, mx_x, mn_y, mx_y;
};
 
struct SegmentTree
{
	Node tree[4*1000*1000];
 
	void combine(int node)
	{
		tree[node].mn_x = min(tree[2*node].mn_x, tree[2*node+1].mn_x);
		tree[node].mx_x = max(tree[2*node].mx_x, tree[2*node+1].mx_x);
		tree[node].mn_y = min(tree[2*node].mn_y, tree[2*node+1].mn_y);
		tree[node].mx_y = max(tree[2*node].mx_y, tree[2*node+1].mx_y);
	}
 
	void build(int node, int l, int r)
	{
		if (l == r)
		{
			tree[node] = {x[l], x[l], y[l], y[l]};
			return;
		}
 
		int mid = (l+r)>>1;
 
		build(2*node, l, mid); build(2*node+1, mid+1, r);
 
		combine(node);
	}
 
	void upd(int node, int l, int r, int pos, int vx, int vy)
	{
		if (l == r)
		{
			tree[node] = {vx, vx, vy, vy};
			return;
		}
 
		int mid = (l+r)>>1;
 
		if (pos <= mid) upd(2*node, l, mid, pos, vx, vy);
		else upd(2*node+1, mid+1, r, pos, vx, vy);
 
		combine(node);
	}
 
	Node query(int node, int l, int r, int a, int b)
	{
		if (l > b || r < a) return {n*m, 0, n*m, 0};
		if (l >= a && r <= b) return tree[node];
 
		int mid = (l+r)>>1;
 
		Node p1 = query(2*node, l, mid, a, b);
		Node p2 = query(2*node+1, mid+1, r, a, b);
 
		return {min(p1.mn_x, p2.mn_x), max(p1.mx_x, p2.mx_x), min(p1.mn_y, p2.mn_y), max(p1.mx_y, p2.mx_y)};
	}
} seg;
 
void give_initial_chart(int H, int W, vector<int> R, vector<int> C)
{
	n = H, m = W;
 
	for (int i = 0; i < n*m; i++)
	{
		x.push_back(R[i]);
		y.push_back(C[i]);
	}
 
	seg.build(1, 0, n*m-1);
}
 
int sub_1(void)
{	
	int mn_x = x[0], mx_x = x[0];
	int mn_y = y[0], mx_y = y[0];
	int ans = 1;
 
	for (int i = 1; i < n*m; i++)
	{
		mn_x = min(mn_x, x[i]); mx_x = max(mx_x, x[i]);
		mn_y = min(mn_y, y[i]); mx_y = max(mx_y, y[i]);
 
		if ((mx_x-mn_x+1)*(mx_y-mn_y+1) == i+1) ans++;
	}
 
	return ans;
}
 
int sub_2(void)
{
	int ans = 0;
 
	for (int i = 0; i < n*m; )
	{
		Node node = seg.query(1, 0, n*m-1, 0, i);
 
		int mn_x = node.mn_x, mx_x = node.mx_x, mn_y = node.mn_y, mx_y = node.mx_y;
 
		if ((mx_x-mn_x+1)*(mx_y-mn_y+1) == i+1) ans++;
 
		i = max(i+1, (mx_x-mn_x+1)*(mx_y-mn_y+1)-1);
	}
 
	return ans;
}
 
int swap_seats(int a, int b)
{
	int xa = x[a], ya = y[a];
	int xb = x[b], yb = y[b];
 
	x[a] = xb, y[a] = yb;
	x[b] = xa, y[b] = ya;
 
	seg.upd(1, 0, n*m-1, a, x[a], y[a]); seg.upd(1, 0, n*m-1, b, x[b], y[b]);
 
	if (n <= 1000 && m <= 1000) return sub_2();
	return sub_1();
}

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 20 / 20
• Subtask 4: 0 / 6
• Subtask 5: 0 / 33
• Subtask 6: 0 / 30