Submission #144287

#	Time	Username	Problem	Language	Result	Execution time	Memory
144287		Minnakhmetov	Seats (IOI18_seats)	C++14	0 / 100	4006 ms	71908 KiB

seats

#include "seats.h"
#include<bits/stdc++.h>

using namespace std;

const int N = 1e6 + 5, INF = 1e9;
int n, m;
vector<int> x, y;
int lx[N], rx[N], ly[N], ry[N], num[N], pos[N];
bool rect[N], tmp[N];

int ans = 0;



int swap_seats_slow(int a, int b) {
	swap(x[a], x[b]);
	swap(y[a], y[b]);

	for (int i = a + 1; i <= b + 1; i++) {
		lx[i] = min(lx[i - 1], x[i - 1]);
		rx[i] = max(rx[i - 1], x[i - 1]);
		ly[i] = min(ly[i - 1], y[i - 1]);
		ry[i] = max(ry[i - 1], y[i - 1]);

		if (rect[i])
			ans--;

		if ((rx[i] - lx[i] + 1) * (ry[i] - ly[i] + 1) == i) {
			rect[i] = 1;
			ans++;
		}
		else {
			rect[i] = 0;
		}
	}

	return ans;
}

struct Node {
	int mn, ct, up;
} t[N * 4];

Node operator + (Node a, Node b) {
	if (a.mn == b.mn) {
		a.ct += b.ct;
		return a;
	}
	if (a.mn < b.mn)
		return a;
	return b;
}

void push(int v, int L, int R) {
	if (t[v].up) {
		if (L != R) {
			t[v * 2].up += t[v].up;
			t[v * 2 + 1].up += t[v].up;
		}
		t[v].mn += t[v].up;
		t[v].up = 0;
	}
}

void upd(int l, int r, int x, int v, int L, int R) {
	push(v, L, R);
	if (l > r)
		return;
	if (l == L && r == R) {
		t[v].up += x;
		push(v, L, R);
	}
	else {
		int m = (L + R) >> 1;
		upd(l, min(m, r), x, v * 2, L, m);
		upd(max(m + 1, l), r, x, v * 2 + 1, m + 1, R);
		t[v] = t[v * 2] + t[v * 2 + 1];
	}
}

void change(int a, int d) {
	if (pos[a] > 0)
		upd(max(num[a], num[pos[a] - 1]), m - 1, d, 1, 0, m - 1);
	if (pos[a] < m - 1)
		upd(max(num[a], num[pos[a] + 1]), m - 1, d, 1, 0, m - 1);
}

int swap_seats_line(int a, int b) {
	change(a, 1);
	change(b, 1);

	if (abs(pos[a] - pos[b]) == 1) {
		upd(max(num[a], num[b]), m - 1, -1, 1, 0, m - 1);
	}

	swap(num[y[a]], num[y[b]]);
	swap(pos[a], pos[b]);

	change(a, -1);
	change(b, -1);

	if (abs(pos[a] - pos[b]) == 1) {
		upd(max(num[a], num[b]), m - 1, 1, 1, 0, m - 1);
	}

	push(1, 0, m - 1);

	return t[1].mn == 1 ? t[1].ct : 0;
}


void init_slow() {
	lx[0] = INF;
	rx[0] = -1;
	ly[0] = INF;
	ry[0] = -1;

	for (int i = 1; i <= n * m; i++) {
		lx[i] = min(lx[i - 1], x[i - 1]);
		rx[i] = max(rx[i - 1], x[i - 1]);
		ly[i] = min(ly[i - 1], y[i - 1]);
		ry[i] = max(ry[i - 1], y[i - 1]);

		if ((rx[i] - lx[i] + 1) * (ry[i] - ly[i] + 1) == i) {
			rect[i] = 1;
			ans++;
		}
	}
}

void init_line() {
	int cur = 0;
	fill(t, t + m * 4, (Node){0, 1, 0});
	for (int i = 0; i < m; i++) {
		cur++;
		tmp[y[i]] = 1;
		if (y[i] > 0 && tmp[y[i] - 1])
			cur--;
		if (y[i] + 1 < m && tmp[y[i] + 1])
			cur--;
		upd(i, i, cur, 1, 0, m - 1);
	}
}

void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
	n = H;
	m = W;
	x = R;
	y = C;

	if (n > 1)
		init_slow();
	else
		init_line();
}

int swap_seats(int a, int b) {
	if (a > b)
		swap(a, b);

	if (n > 1) {
		return swap_seats_slow(a, b);
	}
	return swap_seats_line(a, b);
}

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