Submission #71639

#	Time	Username	Problem	Language	Result	Execution time	Memory
71639		mr_banana	Towns (IOI15_towns)	C++17	25 / 100	40 ms	5520 KiB

towns

#include <bits/stdc++.h>
#include "towns.h"
using namespace std;
const int MN=200,inf=1e9;
int dist[MN][MN];
bool mark[MN][MN];
map<int,int> cnt;
int n;
int getdists(int x){
    int mi=0;
    for(int i=0;i<n;i++){
        if(x!=i && !mark[x][i]){
            dist[x][i]=dist[i][x]=getDistance(x,i);
            mark[x][i]=mark[i][x]=1;
        }
        if(dist[x][i]>dist[x][mi]){
            mi=i;
        }
    }
    return mi;
}
int hubDistance(int N, int sub) {
    cnt.clear();
    memset(mark,0,sizeof mark);
    n=N;
    int u=getdists(0);
    int v=getdists(u);
    getdists(v);
    int ans=inf;
    for(int i=0;i<n;i++){
        int d=(dist[i][v]+dist[i][u]-dist[u][v])/2;
        cnt[dist[i][v]-d]++;
        ans=min(ans,max(dist[i][v],dist[i][u])-d);
    }
    int n1=0,n2=n;
    bool f=0;
    for(auto i:cnt){
        if(max(i.first,dist[u][v]-i.first)!=ans){
            continue;
        }
        n2-=i.second;
        if(n1<=n/2 && n2<=n2 && i.second<=n/2){
            f=1;
        }
        n1+=i.second;
    }
    if(f){
        return ans;
    }
    else{
        return -ans;
    }
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:42:25: warning: self-comparison always evaluates to true [-Wtautological-compare]
         if(n1<=n/2 && n2<=n2 && i.second<=n/2){
                       ~~^~~~
towns.cpp:22:28: warning: unused parameter 'sub' [-Wunused-parameter]
 int hubDistance(int N, int sub) {
                            ^~~

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