Submission #832731

#	Time	Username	Problem	Language	Result	Execution time	Memory
832731		aymanrs	Towns (IOI15_towns)	C++14	48 / 100	13 ms	380 KiB

towns

#include <bits/stdc++.h>
#include "towns.h"
using namespace std;
int hubDistance(int N, int sub) {
	if(sub == 3){
		int d[N][N];
		int wi = 0, wj = 1, md = 0;
		for(int i = 0;i < N;i++){
			d[i][i] = 0;
			for(int j = i+1;j < N;j++) {
				d[i][j] = d[j][i] = getDistance(i, j);
				if(d[i][j] > md){
					md = d[i][j];
					wi = i;
					wj = j;
				}
			}
		}
		vector<int> ci, cj, cci, ccj;
		cci.push_back(wi);
		ccj.push_back(wj);
		for(int i = 0;i < N;i++){
			if(i == wi || i == wj) continue;
			int dlca = (d[i][wi]+d[i][wj]-d[wi][wj])/2;
			md = min(md, max(d[i][wi]-dlca, d[i][wj]-dlca));
		}
		int dlc[N];
		for(int i = 0;i < N;i++){
			if(i == wi || i == wj) continue;
			int dlca = (d[i][wi]+d[i][wj]-d[wi][wj])/2;
			dlc[i] = dlca;
			if(max(d[i][wi]-dlca, d[i][wj]-dlca) != md){
				if(d[i][wi] < d[i][wj]) cci.push_back(i);
				else ccj.push_back(i);
				continue;
			}
			if(!dlca) continue;
			if(d[i][wi] < d[i][wj]) ci.push_back(i);
			else cj.push_back(i);
		}
		bool v[N] = {false};
		bool kek;
		if(ci.empty()) goto kf;
		kek = ccj.size()+cj.size() <= N/2 && cci.size() <= N/2;
		for(int i : ci){
			if(v[i]) continue;
			v[i] = true;
			int c = 1;
			for(int j : ci){
				if(v[j] || d[i][j] == dlc[i]+dlc[j]) continue;
				v[j] = true;
				c++;
			}
			kek &= c <= N/2;
		}
		if(kek) return md;
		kf:
		if(cj.empty()) return -md;
		kek = ccj.size() <= N/2 && cci.size()+ci.size() <= N/2;
		fill(v, v+N, false);
		for(int i : cj){
			if(v[i]) continue;
			v[i] = true;
			int c = 1;
			for(int j : cj){
				if(v[j] || d[i][j] == dlc[i]+dlc[j]) continue;
				v[j] = true;
				c++;
			}
			kek &= c <= N/2;
		}
		if(kek) return md;
		return -md;
	}
	int md = 0, wi = 1, wii;
	for(int i = 1;i < N;i++){
		int c = getDistance(0, i);
		if(c > md){
			md = c;
			wi = i;
		}
	}
	int d[N], dw[N];
	d[wi]=0;
	md = 0;
	wii = 0;
	for(int i = 0;i < N;i++){
		if(i == wi) continue;
		d[i] = getDistance(wi, i);
		if(d[i] > md){
			md = d[i];
			wii = i;
		}
	}
	dw[wii] = 0;
	dw[wi] = md;
	for(int i = 0;i < N;i++) if(i != wi && i != wii) dw[i] = getDistance(wii, i);
	for(int i = 0;i < N;i++){
		if(i == wi || i == wii) continue;
		int dlca = (d[i]+dw[i]-d[wii])/2;
		md = min(md, max(d[i]-dlca, dw[i]-dlca));
	}
	int C[2][2] = {{0}};
	for(int i = 0;i < N;i++){
		if(i == wi){
			C[0][0]++;
			continue;
		}
		if(i == wii){
			C[1][0]++;
			continue;
		}
		int dlca = (d[i]+dw[i]-d[wii])/2;
		dlca = max(d[i]-dlca, dw[i]-dlca);
		C[d[i] >= dw[i]][dlca==md]++;
	}
	N/=2;
	if(!C[0][1]) goto st;
	if(C[0][1] <= N && C[0][0] <= N && C[1][0]+C[1][1] <= N) return md;
	st:
	if(!C[1][1]) return -md;
	if(C[1][1] <= N && C[1][0] <= N && C[0][0]+C[0][1] <= N) return md;
	return -md;
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:44:30: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |   kek = ccj.size()+cj.size() <= N/2 && cci.size() <= N/2;
      |         ~~~~~~~~~~~~~~~~~~~~~^~~~~~
towns.cpp:44:51: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |   kek = ccj.size()+cj.size() <= N/2 && cci.size() <= N/2;
      |                                        ~~~~~~~~~~~^~~~~~
towns.cpp:59:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   59 |   kek = ccj.size() <= N/2 && cci.size()+ci.size() <= N/2;
      |         ~~~~~~~~~~~^~~~~~
towns.cpp:59:51: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   59 |   kek = ccj.size() <= N/2 && cci.size()+ci.size() <= N/2;
      |                              ~~~~~~~~~~~~~~~~~~~~~^~~~~~

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