Submission #421720

#	Time	Username	Problem	Language	Result	Execution time	Memory
421720		alireza_kaviani	Seats (IOI18_seats)	C++11	37 / 100	4081 ms	130064 KiB

seats

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

#define all(x)		(x).begin() , (x).end()

const int MAXN = 1e6 + 10;

int n , h , w , ans , A[2][MAXN] , first[2][MAXN] , valid[MAXN] , mn[2][MAXN] , mx[2][MAXN] , MN[2] , MX[2];
vector<int> vec[2][MAXN];

void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
	h = H; w = W; n = h * w;
	for(int i = 0 ; i < n ; i++){
		A[0][i] = mn[0][i] = mx[0][i] = R[i];
		A[1][i] = mn[1][i] = mx[1][i] = C[i];
		vec[0][A[0][i]].push_back(i);
		vec[1][A[1][i]].push_back(i);
	}
	for(int i = 0 ; i < 2 ; i++){
		for(int j = 1 ; j < n ; j++){
			mn[i][j] = min(mn[i][j] , mn[i][j - 1]);
			mx[i][j] = max(mx[i][j] , mx[i][j - 1]);
		}
	}
	for(int i = 0 ; i < n ; i++){
		int x = (mx[0][i] - mn[0][i] + 1) , y = (mx[1][i] - mn[1][i] + 1);
		if(x * y == i + 1){
			valid[i] = 1;
			ans++;
		}
	}
	for(int i = 0 ; i < h ; i++)	first[0][i] = *min_element(all(vec[0][i]));
	for(int i = 0 ; i < w ; i++)	first[1][i] = *min_element(all(vec[1][i]));
}

void change(int i , int x , int a , int b){
	for(int j = 0 ; j < vec[i][x].size() ; j++){
		if(vec[i][x][j] == a)	vec[i][x][j] = b;
	}
	first[i][x] = *min_element(all(vec[i][x]));
}

int swap_seats(int a, int b) {
	if(a > b)	swap(a , b);
	if(h > 1000 || w > 1000){
		for(int i = 0 ; i < 2 ; i++){
			swap(A[i][a] , A[i][b]);
			mn[i][0] = mx[i][0] = A[i][0];
			for(int j = max(a , 1) ; j < b ; j++){
				mn[i][j] = min(A[i][j] , mn[i][j - 1]);
				mx[i][j] = max(A[i][j] , mx[i][j - 1]);
			}
		}
		for(int i = a ; i < b ; i++){
			ans -= valid[i]; valid[i] = 0;
			int x = (mx[0][i] - mn[0][i] + 1) , y = (mx[1][i] - mn[1][i] + 1);
			if(x * y == i + 1){
				valid[i] = 1;
				ans++;
			}
		}
		return ans;
	}
	int ans = 0;
	for(int i = 0 ; i < 2 ; i++){
		if(A[i][a] == A[i][b])	continue;
		change(i , A[i][a] , a , b);
		change(i , A[i][b] , b , a);
		swap(A[i][a] , A[i][b]);
	}
	vector<int> vec;
	for(int i = 0 ; i < h ; i++)	vec.push_back(first[0][i]);
	for(int i = 0 ; i < w ; i++)	vec.push_back(first[1][i]);
	sort(all(vec));
	vec.resize(unique(all(vec)) - vec.begin());
	vec.push_back(n);
	MN[0] = MN[1] = MAXN;
	MX[0] = MX[1] = -1;
	for(int i = 0 ; i + 1 < vec.size() ; i++){
		int pos = vec[i];
		MN[0] = min(MN[0] , A[0][pos]); MX[0] = max(MX[0] , A[0][pos]);
		MN[1] = min(MN[1] , A[1][pos]); MX[1] = max(MX[1] , A[1][pos]);
		int x = (MX[0] - MN[0] + 1) , y = (MX[1] - MN[1] + 1);
		if(vec[i] < x * y && x * y <= vec[i + 1])	ans++;
	}
	return ans;
}

Compilation message (stderr)

seats.cpp: In function 'void change(int, int, int, int)':
seats.cpp:38:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |  for(int j = 0 ; j < vec[i][x].size() ; j++){
      |                  ~~^~~~~~~~~~~~~~~~~~
seats.cpp: In function 'int swap_seats(int, int)':
seats.cpp:80:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |  for(int i = 0 ; i + 1 < vec.size() ; i++){
      |                  ~~~~~~^~~~~~~~~~~~

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