# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
592211 | Deepesson | Towns (IOI15_towns) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define MAX 115
int getDistance(int i, int j);
int hubDistance(int N, int sub);
typedef std::pair<int,int> pii;
int dist[MAX][2];
pii MaisDistante(int N,int x,int p){
int best=-1,alvo=0;
for(int i=0;i!=N;++i){
if(i==x)continue;
int d = getDistance(i,x);
if(d>best){
best=d;
alvo=i;
}
dist[i][p]=d;
}
return {best,alvo};
}
///Queries usadas: 3N-3
int hubDistance(int N, int sub) {
pii alpha = MaisDistante(N,0,1);
pii beta = MaisDistante(N,alpha.second,0);
MaisDistante(N,beta.second,1);
int d = beta.first;
int ans=1e9;
int eixo;
int grupos[2]={1,1};
std::vector<int> fora;
for(int i=0;i!=N;++i){
if(i==alpha.second||i==beta.second)continue;
int a = dist[i][0];
int b = dist[i][1];
int soma = a+b;
int subt = soma-d;
int base = subt/2;
int custo = std::max(a,b)-base;
if(custo<ans){///Fora da sub de A ou B
eixo=i;
ans=custo;
}
}
if(sub<=2)
return ans;
for(int i=0;i!=N;++i){
if(i==alpha.second||i==beta.second)continue;
int a = dist[i][0];
int b = dist[i][1];
int soma = a+b;
int subt = soma-d;
int base = subt/2;
int custo = std::max(a,b)-base;
if(custo==ans){///Fora da sub de A ou B
fora.push_back(i);
}else {///Na subarvore de A ou B
if(a>b)grupos[0]++;else grupos[1]++;
}
}
int lim=N/2;
if(grupos[0]>lim||grupos[1]>lim)return -R;
///Para a sub 3
int sum = grupos[0]+grupos[1];
if(sum>lim)return -R;
return R;
}