Submission #78707

#	Time	Username	Problem	Language	Result	Execution time	Memory
78707		tincamatei	Seats (IOI18_seats)	C++14	100 / 100	2145 ms	151180 KiB

seats

#pragma GCC target("avx,avx2,sse,sse2")
#pragma GCC optimize("Ofast")
#include "seats.h"
#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 1000000;

int val[1+4*MAX_N], fr[1+4*MAX_N];
int lazy[1+4*MAX_N];
int initsum[MAX_N+1];

static inline void pushLazy(int nod, int l, int r) {
	if(lazy[nod] != 0) {
		val[nod] += lazy[nod];
		if(l < r) {
			lazy[2 * nod] += lazy[nod];
			lazy[2 * nod + 1] += lazy[nod];
		}
		lazy[nod] = 0;
	}
}

inline void init(int l, int r, int nod = 1) {
	if(l == r) {
		val[nod] = initsum[l];
		fr[nod] = 1;
	}
	else if(l < r){
		int mid = (l + r) / 2;
		init(l, mid, 2 * nod);
		init(mid + 1, r, 2 * nod + 1);
		val[nod] = min(val[2 * nod], val[2 * nod + 1]);
		if(val[2 * nod] == val[nod])
			fr[nod] += fr[2 * nod];
		if(val[2 * nod + 1] == val[nod])
			fr[nod] += fr[2 * nod + 1];
	}
}

inline void update(int i, int j, int valU, int l, int r, int nod = 1) {
	pushLazy(nod, l, r);
	if(r < i || j < l)
		return;
	
	int mid = (l + r) / 2;
	if(i <= l && r <= j) {
		lazy[nod] += valU;
		pushLazy(nod, l, r);
		return;
	}
	update(i, j, valU, l, mid, 2 * nod);
	update(i, j, valU, mid + 1, r, 2 * nod + 1);
	val[nod] = val[2 * nod], fr[nod] = fr[2 * nod];
	if(val[2 * nod + 1] < val[nod]) {
		val[nod] = val[2 * nod + 1];
		fr[nod] = fr[2 * nod + 1];
	} else if(val[nod] == val[2 * nod + 1])
		fr[nod] += fr[2 * nod + 1];
}

int N, H, W;
int cells[4];
vector<vector<int> > matr;

vector<int> R, C;

static inline void activateSqr(int l, int c, int x) {
	cells[0] = matr[l][c];
	cells[1] = matr[l + 1][c];
	cells[2] = matr[l][c + 1];
	cells[3] = matr[l + 1][c + 1];
	std::sort(cells, cells + 4);
	update(cells[0], cells[1] - 1, x, 0, N - 1);
	update(cells[2], cells[3] - 1, 4 * x, 0, N - 1);
}

void give_initial_chart(int H, int W, std::vector<int> _R, std::vector<int> _C) {
	N = H * W;
	R = _R;
	C = _C;
	matr.resize(H+2, vector<int>(W+2, N));

	for(int i = 0; i < N; ++i) {
		R[i]++;
		C[i]++;
		matr[R[i]][C[i]] = i;
	}
	for(int i = 0; i <= H; ++i)
		for(int j = 0; j <= W; ++j) {
			cells[0] = matr[i][j];
			cells[1] = matr[i + 1][j];
			cells[2] = matr[i][j + 1];
			cells[3] = matr[i + 1][j + 1];
			std::sort(cells, cells + 4);
			initsum[cells[0]]++;
			initsum[cells[1]]--;
			initsum[cells[2]]+=4;
			initsum[cells[3]]-=4;
		}
	
	for(int i = 1; i < N; ++i)
		initsum[i] += initsum[i - 1];
	init(0, N - 1, 1);
}

int dr[] = {0,-1, 0, -1};
int dc[] = {0, 0,-1, -1};

int swap_seats(int a, int b) {
	vector<pair<int, int> > yeet;
	for(int i = 0; i < 4; ++i) {
		yeet.push_back(make_pair(R[a] + dr[i], C[a] + dc[i]));
		yeet.push_back(make_pair(R[b] + dr[i], C[b] + dc[i]));
	}
	std::sort(yeet.begin(), yeet.end());
	yeet.resize(unique(yeet.begin(), yeet.end()) - yeet.begin());	
	for(int i = 0; i < yeet.size(); ++i)
		activateSqr(yeet[i].first, yeet[i].second, -1);
	swap(R[a], R[b]);
	swap(C[a], C[b]);
	swap(matr[R[a]][C[a]], matr[R[b]][C[b]]);
	for(int i = 0; i < yeet.size(); ++i)
		activateSqr(yeet[i].first, yeet[i].second, 1);
	
	if(val[1] != 4)
		return 0;
	return fr[1];
}

Compilation message (stderr)

seats.cpp: In function 'int swap_seats(int, int)':
seats.cpp:119:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < yeet.size(); ++i)
                 ~~^~~~~~~~~~~~~
seats.cpp:124:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < yeet.size(); ++i)
                 ~~^~~~~~~~~~~~~

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