Submission #206364

#	Time	Username	Problem	Language	Result	Execution time	Memory
206364		batmend	Seats (IOI18_seats)	C++14	100 / 100	3380 ms	69592 KiB

seats

#include "seats.h"
#include<bits/stdc++.h>
using namespace std;

const int N = 1000005;

int n, m, k;
int posx[N], posy[N];
int num[N];
int minv[2100000], minc[2100000], lazy[2100000];						// initial values are 0, thus, minv is 0 for every val;
int a[5];

void build(int id, int l, int r);
int get(int x, int y);
void supd(int id, int l, int r, int ll, int rr, int val);
void upd(int x, int y, int v);
void change(int x, int y, int v);

void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
	n = H;
	m = W;
	k = H * W;
	build(1, 0, k - 1);    			// initially every val is 0;
	for (int i = 0; i < k ; i++) {
		posy[i] = R[i];
		posx[i] = C[i];
		num[posy[i]*m+posx[i]]=i;
	}
	for (int i = 0; i <= n; i++) {
		for (int j = 0; j <= m; j++) {
			upd(j, i, 1);
		}
	}
}

int swap_seats(int a, int b) {
	change(posx[a], posy[a], b);
	change(posx[b], posy[b], a);
	swap(posx[a], posx[b]);
	swap(posy[a], posy[b]);
	return minc[1];
}

void change(int x, int y, int v) {
	for (int i = 0; i < 2; i++) {
		for (int j = 0; j < 2; j++) {
			upd(x+i, y+j, -1);
		}
	}
	num[y * m + x] = v;
	for (int i = 0; i < 2; i++) {
		for (int j = 0; j < 2; j++) {
			upd(x+i, y+j, 1);
		}
	}
}

void build(int id, int l, int r) {
	minc[id] = r - l + 1;
	if (r == l) return;
	int mid = (l + r) / 2;
	build(2 * id, l, mid);
	build(2 * id + 1, mid + 1, r);
}

int get(int x, int y) {
	if (x < 0 || x >= m || y < 0 || y >= n) return k;
	return num[y * m + x];
}

void supd(int id, int l, int r, int ll, int rr, int v) {
	if (l > rr || r < ll) return;
	if (ll <= l && r <= rr) {
		lazy[id] += v;
		minv[id] += v;
		return;
	}
	int mid = (l + r) / 2;
	supd(2*id, l, mid, ll, rr, v);
	supd(2*id + 1, mid + 1, r, ll, rr, v);
	if (minv[2*id] > minv[2*id+1]) {
		minv[id] = minv[2*id+1];
		minc[id] = minc[2*id+1];
	}
	if (minv[2*id] < minv[2*id+1]) {
		minv[id] = minv[2*id];
		minc[id] = minc[2*id];
	}
	if (minv[2*id] == minv[2*id + 1]) {
		minv[id] = minv[2*id];
		minc[id] = minc[2*id] + minc[2*id + 1];
	}
	minv[id] += lazy[id];
}

void upd(int x, int y, int v) {
	for (int i = 0; i < 2; i++) {
		for (int j = 0; j < 2; j++) {
			a[2 * i + j] = get(x - i, y - j);
		}
	}
	sort (a, a + 4);
	if (a[0] < a[1]) supd(1, 0, k - 1, a[0], a[1] - 1, v);
	if (a[2] < a[3]) supd(1, 0, k - 1, a[2], a[3] - 1, v);
}

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