Submission #399747

#	Time	Username	Problem	Language	Result	Execution time	Memory
399747		peuch	Towns (IOI15_towns)	C++17	48 / 100	27 ms	1104 KiB

towns

#include "towns.h"
#include<bits/stdc++.h>
using namespace std;
 
const int MAXN = 310;
 
int dist[MAXN][MAXN];
int marc[MAXN][MAXN];

int getD(int i, int j){
	if(marc[i][j]) return dist[i][j];
	marc[i][j] = marc[j][i] = 1;
	if(i == j) return dist[i][j] = dist[j][i] = 0;
	return dist[i][j] = dist[j][i] = getDistance(i, j);
}
 
int hubDistance(int N, int sub) {
	int p1 = 0, p2 = 0;
	int maxi = 0;
	memset(dist, 0, sizeof(dist));
	memset(marc, 0, sizeof(marc));
	for(int i = 0; i < N; i++){
		int aux = getD(0, i);
		if(aux > maxi) p1 = i, maxi = aux;
	}
	maxi = 0;
	for(int i = 0; i < N; i++)
		if(getD(p1, i) > maxi) maxi = getD(p1, i), p2 = i;
	
	int diam = getD(p1, p2);
	int ans = 1e8;
	for(int i = 0; i < N; i++){
		int x = (diam + getD(p1, i) - getD(p2, i)) / 2;
		ans = min(ans, max(x, diam - x));
	}
	
	if(sub <= 2) return ans;
	
	int lSize = 0, rSize = 0;
	vector<int> lMid, rMid;
	for(int i = 0; i < N; i++){
		int x = (diam + getD(p1, i) - getD(p2, i)) / 2;
		if(x < min(ans, diam - ans)) lSize++;
		else if(x == min(ans, diam - ans)) lMid.push_back(i); 
		else if(x == max(ans, diam - ans)) rMid.push_back(i);
		else rSize++;
	}
	if(sub <= 4){
		if(lSize > N / 2 || rSize > N / 2 || lMid.size() > N / 2 || rMid.size() > N / 2) return -ans;
		return ans;
	}
	
	if(lSize > N / 2 || rSize > N / 2) return -ans;
	else if(lMid.size() > N / 2){
		stack<int> pilha;
		for(int i = 0; i < lMid.size(); i++){
			if(pilha.empty()) pilha.push(lMid[i]);
			else{
				int aux = getD(p1, pilha.top());
				int x = (aux + getD(p1, lMid[i]) - getD(pilha.top(), lMid[i])) / 2;
				if(x == min(ans, diam - ans)) pilha.pop();
				else pilha.push(lMid[i]);
			}
		}
		if(pilha.empty()) return ans;
		int k = pilha.top();
		int cnt = 0;
		for(int i = 0; i < lMid.size(); i++){
			int aux = getD(p1, k);
			int x = (aux + getD(p1, lMid[i]) - getD(k, lMid[i])) / 2;
			if(x > min(ans, diam - ans)) cnt++;
		}
		if(cnt > N / 2) return -ans;
		return ans;
	}
	else if(rMid.size() > N / 2){
		stack<int> pilha;
		for(int i = 0; i < rMid.size(); i++){
			if(pilha.empty()) pilha.push(rMid[i]);
			else{
				int aux = getD(p1, pilha.top());
				int x = (aux + getD(p1, rMid[i]) - getD(pilha.top(), rMid[i])) / 2;
				if(x == max(ans, diam - ans)) pilha.pop();
				else pilha.push(rMid[i]);
			}
		}
		if(pilha.empty()) return ans;
		int k = pilha.top();
		int cnt = 0;
		for(int i = 0; i < rMid.size(); i++){
			int aux = getD(p1, k);
			int x = (aux + getD(p1, rMid[i]) - getD(k, rMid[i])) / 2;
			if(x > max(ans, diam - ans)) cnt++;
		}
		if(cnt > N / 2) return -ans;
		return ans;
	}
	return ans;
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:49:52: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |   if(lSize > N / 2 || rSize > N / 2 || lMid.size() > N / 2 || rMid.size() > N / 2) return -ans;
      |                                        ~~~~~~~~~~~~^~~~~~~
towns.cpp:49:75: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |   if(lSize > N / 2 || rSize > N / 2 || lMid.size() > N / 2 || rMid.size() > N / 2) return -ans;
      |                                                               ~~~~~~~~~~~~^~~~~~~
towns.cpp:54:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   54 |  else if(lMid.size() > N / 2){
      |          ~~~~~~~~~~~~^~~~~~~
towns.cpp:56:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |   for(int i = 0; i < lMid.size(); i++){
      |                  ~~^~~~~~~~~~~~~
towns.cpp:68:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |   for(int i = 0; i < lMid.size(); i++){
      |                  ~~^~~~~~~~~~~~~
towns.cpp:76:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   76 |  else if(rMid.size() > N / 2){
      |          ~~~~~~~~~~~~^~~~~~~
towns.cpp:78:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |   for(int i = 0; i < rMid.size(); i++){
      |                  ~~^~~~~~~~~~~~~
towns.cpp:90:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |   for(int i = 0; i < rMid.size(); i++){
      |                  ~~^~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 12 / 12
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 13 / 13
• Subtask 6: 0 / 39