Submission #616043

#	Time	Username	Problem	Language	Result	Execution time	Memory
616043		Apiram	Towns (IOI15_towns)	C++14	0 / 100	15 ms	352 KiB

towns

#include "towns.h"
#include <bits/stdc++.h>
using namespace std;
int hubDistance(int N, int sub) {
	int root = 0;
	vector<int>dist(N),dist2(N);
	for (int i = 0;i<N;++i){
		if (i == root)dist[i] = 0;
		else dist[i] = getDistance(i,root);
	}
	for (int i = 0;i<N;++i){
		if (dist[i] > dist[root]){
			root = i;
		}
	}
	for (int i = 0;i<N;++i){
		if (i == root)dist2[i] = 0;
		else if (i == 0)dist2[i] = dist[root];
		else dist2[i] = getDistance(i,root);
	}
	int root2 = root;
	for (int i = 0;i<N;++i){
		if (dist2[i] > dist2[root2])root2 = i;
	}
	int answer = dist2[root2];
	vector<int>dist3(N);
	for (int i = 0;i<N;++i){
		if (i == root2){
			dist3[i] = 0;
		}
		else if (i == 0)dist3[i] = dist[root2];
		else if (i == root)dist3[i] = dist2[root2];
		else{
			dist3[i] = dist[i] + dist[root2] - 2 * (dist[root] + dist[i] - dist2[i])/2;
		}
	}
	for (int i = 0;i<N;++i){
		int x = (dist2[i] + dist3[i] - dist2[root2])/2;
		answer = min(answer,max(dist2[i] - x,dist3[i] - x)); 
	}
	/*for (int i = 0;i<N;++i){
		int x = (dist[i] + dist2[i] - dist[root2])/2;
		if (answer == max(dist[i] - x,dist2[i] - x)){
			int sub1 = 0,sub2 = 0,sub3 = 0,sub4 = 0;
			for (int j = 0;j<N;++j){
				if (dist[j] <= dist[i] - x){
					sub1++;
				}
				else if (dist2[j]<=dist2[i] - x){
					sub2++;
				}
				else if (getDistance(i,j) <=x)sub3++;
				else sub4++;
				if (sub4 > N / 2 + 2)break;
				if (sub3 > N / 2)break;
			}
			while (sub4 > N/2){
				--sub4;
				++sub3;
			}
			if (max({sub1,sub2,sub3,sub4}) <=N/2){
				return answer;
			}
			break;
		}
	}
	*/
	return -answer;
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:4:28: warning: unused parameter 'sub' [-Wunused-parameter]
    4 | int hubDistance(int N, int sub) {
      |                        ~~~~^~~

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