Submission #1090673

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090673		owoovo	Towns (IOI15_towns)	C++17	0 / 100	1 ms	348 KiB

towns

#include "towns.h"
#include<bits/stdc++.h>
#define ll long long
#define F first 
#define S second 
using namespace std;
const ll maxn=1e18;
ll to0[120],tor1[120],tor2[120];
ll r1,r2;
int getd(int a,int b){
	if(a==0)return to0[b];
	else if(b==0)return to0[a];
	return getDistance(a,b);
}
int hubDistance(int N, int sub) {
	for(int i=1;i<N;i++)to0[i]=getDistance(0,i);
	ll maxn=0,pos=0;
	for(int i=0;i<N;i++){
		if(to0[i]>maxn){
			maxn=to0[i];
			pos=i;
		}
	}
	r1=pos;
	for(int i=0;i<N;i++)tor1[i]=getDistance(r1,i);
	maxn=0,pos=0;
	for(int i=0;i<N;i++){
		if(tor1[i]>maxn){
			maxn=tor1[i];
			pos=i;
		}
	}
	r2=pos;
	for(int i=0;i<N;i++)tor2[i]=getDistance(r2,i);
	vector<pair<ll,ll>> vc;
	for(int i=0;i<N;i++){
		//cout<<i<<" "<<tor1[r2]<<" "<<tor1[i]<<" "<<tor2[i]<<"\n";
		ll dis=(tor1[r2]+tor1[i]-tor2[i])/2;
		vc.push_back({dis,tor1[i]-dis});
	}
	ll ans=maxn;
	for(int i=0;i<N;i++){
		ans=min(ans,max(vc[i].F,tor1[r2]-vc[i].F));
	}
	vector<ll> want;
	for(int i=0;i<N;i++){
		if(ans==max(vc[i].F,tor1[r2]-vc[i].F)){
			want.push_back(vc[i].F);
		}
	}
	int ok=0;
	for(auto dis:want){
		int s=0,m=0,l=0;
		vector<int> now;
		for(int i=0;i<N;i++){
			if(vc[i].F<dis)s++;
			else if(vc[i].F==dis)now.push_back(i);
			else l++;
		}
		if(s>N/2||l>N/2)continue;
		int vis[120]={0},OK=1;
		for(auto x:now){
			if(vis[x])continue;
			int bk=1;
			for(auto y:now){
				if(vis[y])continue;
				int dd=getd(x,y);
				if(dd<vc[x].S+vc[y].S){
					vis[y]=1;
					bk++;
				}
			}
			if(bk>N/2)OK=0;
		}
		ok|=OK;
	}
	return ok==1?ans:-ans;
}

Compilation message (stderr)

towns.cpp: In function 'int getd(int, int)':
towns.cpp:11:22: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   11 |  if(a==0)return to0[b];
      |                 ~~~~~^
towns.cpp:12:27: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   12 |  else if(b==0)return to0[a];
      |                      ~~~~~^
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:17:5: warning: declaration of 'maxn' shadows a global declaration [-Wshadow]
   17 |  ll maxn=0,pos=0;
      |     ^~~~
towns.cpp:7:10: note: shadowed declaration is here
    7 | const ll maxn=1e18;
      |          ^~~~
towns.cpp:25:42: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   25 |  for(int i=0;i<N;i++)tor1[i]=getDistance(r1,i);
      |                                          ^~
towns.cpp:34:42: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   34 |  for(int i=0;i<N;i++)tor2[i]=getDistance(r2,i);
      |                                          ^~
towns.cpp:53:11: warning: unused variable 'm' [-Wunused-variable]
   53 |   int s=0,m=0,l=0;
      |           ^
towns.cpp:77:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   77 |  return ok==1?ans:-ans;
      |         ~~~~~^~~~~~~~~
towns.cpp:15:28: warning: unused parameter 'sub' [-Wunused-parameter]
   15 | 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