Submission #891836

# Submission time Handle Problem Language Result Execution time Memory
891836 2023-12-24T07:49:16 Z abcvuitunggio Towns (IOI15_towns) C++17
13 / 100
12 ms 860 KB
#include "towns.h"
#include <bits/stdc++.h>
using namespace std;
int n,dist[111][111],u,v,R,sz[2],p[111];
int d(int u, int v){
    if (u==v)
        return 0;
    if (u>v)
        swap(u,v);
    if (dist[u][v])
        return dist[u][v];
    return dist[u][v]=getDistance(u,v);
}
int f(int i){
    return (p[i]==i?i:p[i]=f(p[i]));
}
void unite(int i, int j){
    p[f(j)]=f(i);
}
int calc(vector <int> a){
    if (a.empty())
        return -1;
    if (a.size()==1)
        return a[0];
    vector <int> ve;
    for (int i=0;i<a.size();i+=2){
        int x=a[i],y=a[i+1];
        if (d(x,y)*2<d(x,u)+d(x,v)+d(y,u)+d(y,v)-d(u,v)*2){
            unite(x,y);
            ve.push_back(x);
        }
    }
    return calc(ve);
}
int hubDistance(int N, int sub){
    n=N;
    iota(p,p+n,0);
    memset(dist,0,sizeof(dist));
    pair <int, int> mx={0,-1};
    for (int i=0;i<N;i++)
        mx=max(mx,{d(0,i),i});
    u=mx.second;
    mx={0,-1};
    for (int i=0;i<N;i++)
        mx=max(mx,{d(u,i),i});
    v=mx.second,R=1e9,sz[0]=sz[1]=0;
	for (int i=0;i<N;i++)
        R=min(R,abs(d(i,u)-d(i,v)));
    vector <int> a,b,tmp;
    for (int i=0;i<N;i++){
        int val=d(i,u)-d(i,v);
        if (val<-R)
            sz[0]++;
        if (val==-R)
            a.push_back(i);
        if (val==R)
            b.push_back(i);
        if (val>R)
            sz[1]++;
    }
    if (!R)
        b.clear();
    R=(R+d(u,v))/2;
    if (max(sz[0],sz[1])>N/2)
        return -R;
    if (min(sz[1]+b.size(),sz[0]+a.size())>N/2)
        return -R;
    if (max(a.size(),sz[1]+b.size())<=N/2)
        return R;
    if (max(b.size(),sz[0]+a.size())<=N/2)
        return R;
    if (b.size()+sz[1]>N/2)
        swap(a,b);
    int w=calc(a),cnt=0;
    if (w==-1)
        return R;
    for (int i:a)
        if (i!=w&&i==f(i))
            if (d(w,i)*2<d(w,u)+d(w,v)+d(i,u)+d(i,v)-d(u,v)*2)
                unite(w,i);
    for (int i:a)
        cnt+=(f(i)==w);
    return (cnt>N/2?-R:R);
}

Compilation message

towns.cpp: In function 'int d(int, int)':
towns.cpp:5:18: warning: declaration of 'v' shadows a global declaration [-Wshadow]
    5 | int d(int u, int v){
      |              ~~~~^
towns.cpp:4:24: note: shadowed declaration is here
    4 | int n,dist[111][111],u,v,R,sz[2],p[111];
      |                        ^
towns.cpp:5:11: warning: declaration of 'u' shadows a global declaration [-Wshadow]
    5 | int d(int u, int v){
      |       ~~~~^
towns.cpp:4:22: note: shadowed declaration is here
    4 | int n,dist[111][111],u,v,R,sz[2],p[111];
      |                      ^
towns.cpp: In function 'int calc(std::vector<int>)':
towns.cpp:26:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for (int i=0;i<a.size();i+=2){
      |                  ~^~~~~~~~~
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:66:43: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   66 |     if (min(sz[1]+b.size(),sz[0]+a.size())>N/2)
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
towns.cpp:68:37: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   68 |     if (max(a.size(),sz[1]+b.size())<=N/2)
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
towns.cpp:70:37: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   70 |     if (max(b.size(),sz[0]+a.size())<=N/2)
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
towns.cpp:72:23: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   72 |     if (b.size()+sz[1]>N/2)
      |         ~~~~~~~~~~~~~~^~~~
towns.cpp:35:28: warning: unused parameter 'sub' [-Wunused-parameter]
   35 | int hubDistance(int N, int sub){
      |                        ~~~~^~~
# Verdict Execution time Memory Grader output
1 Correct 10 ms 348 KB Output is correct
2 Correct 8 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 11 ms 532 KB Output is correct
5 Correct 12 ms 348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 9 ms 860 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 11 ms 600 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -