oj.uz

Submission #827877

# Submission time Handle Problem Language Result Execution time Memory
827877 2023-08-16T21:18:44 Z I_Love_EliskaM_ Towns (IOI15_towns) C++17
61 / 100
 14 ms 860 KB 
#include "towns.h"
#include <bits/stdc++.h>
using namespace std;
#define forn(i,n) for(int i=0;i<n;++i)
#define pb push_back
#define all(x) x.begin(), x.end()
#define pi pair<int,int>
#define f first
#define s second
const int inf=1e9+9;
     
int p1(int n) {
  vector<int> a(n), b(n), c(n);
  int f=0;
  forn(i,n) {
    a[i]=getDistance(0,i);
    if (a[i]>a[f]) f=i;
  }
  int s=0;
  forn(i,n) {
    b[i]=getDistance(f,i);
    if (b[i]>b[s]) s=i;
  }
  forn(i,n) {
    c[i]=getDistance(s,i);
  }

  set<int> st;

  vector<int> d(n);
  map<int,vector<int>> ok;

  forn(i,n) {
    if (i==f || i==s) continue;
    int x=b[i], y=c[i], z=b[s];
    int A=(x-y+z)/2;
    d[i]=x-A;
    st.insert(A);
    ok[A].pb(i);
  }

  int ans=inf;
  for(auto&x:st) {
    int y=b[s]-x;
    ans=min(ans,max(x,y));
  }
  int l=1;
  for(auto&x:st) {
    int y=b[s]-x;
    if (max(x,y)!=ans) {
      l+=ok[x].size();
      continue;
    }
    int r=n-ok[x].size()-l;
    if (max(l,r)>n/2) continue;
    int t=ok[x].size();
    if (t<=n/2) return ans;
  }

  return -ans;
}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int p5(int n) {
  vector<int> a(n), b(n), c(n);
  int f=0;
  forn(i,n) {
    a[i]=getDistance(0,i);
    if (a[i]>a[f]) f=i;
  }
  int s=0;
  forn(i,n) {
    b[i]=getDistance(f,i);
    if (b[i]>b[s]) s=i;
  }
  forn(i,n) {
    c[i]=getDistance(s,i);
  }

  set<int> st;

  vector<int> d(n);
  map<int,vector<int>> ok;

  forn(i,n) {
    if (i==f || i==s) continue;
    int x=b[i], y=c[i], z=b[s];
    int A=(x-y+z)/2;
    d[i]=x-A;
    st.insert(A);
    ok[A].pb(i);
  }

  int ans=inf;
  for(auto&x:st) {
    int y=b[s]-x;
    ans=min(ans,max(x,y));
  }
  int l=1;
  int last=-1;
  for(auto&x:st) {
    l+=ok[last].size(); last=x;
    int y=b[s]-x;
    if (max(x,y)!=ans) continue;
    int r=n-ok[x].size()-l;
    if (max(l,r)>n/2) continue;
    int t=ok[x].size();
    if (t<=n/2) return ans;
    vector<pi> a,b;
    for(auto&v:ok[x]) a.pb({v,1});
    while (a.size()>1) {
      int k = a.size();
      for (int i=0; i+1<a.size(); i+=2) {
        int z = getDistance(a[i].f,a[i+1].f);
        int x = d[a[i].f], y = d[a[i+1].f];
        if (z==x+y) {
          if (a[i].s > a[i+1].s) b.pb(a[i]);
          else b.pb(a[i+1]);
          continue;
        }
        b.pb({a[i].f,a[i].s+a[i+1].s});
      }
      if (k&1) b.pb(a.back());
      a=b;
      b.clear();
    }
    int u=a[0].f;
    int sz=0;
    for(auto&v:ok[x]) {
      int z = getDistance(u,v);
      int x = d[u], y = d[v];
      if (z<x+y) ++sz;
    }
    if (sz<=n/2) return ans;
  }

  return -ans;
}

int hubDistance(int n, int sub) {
  if (sub<=2 || sub==4) return p1(n);
  if (sub>=3) return p5(n);
  return 0;
}

Compilation message

towns.cpp: In function 'int p1(int)':
towns.cpp:51:21: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   51 |       l+=ok[x].size();
      |                     ^
towns.cpp:54:25: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   54 |     int r=n-ok[x].size()-l;
      |           ~~~~~~~~~~~~~~^~
towns.cpp:56:21: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   56 |     int t=ok[x].size();
      |           ~~~~~~~~~~^~
towns.cpp: In function 'int p5(int)':
towns.cpp:102:22: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  102 |     l+=ok[last].size(); last=x;
      |                      ^
towns.cpp:105:25: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  105 |     int r=n-ok[x].size()-l;
      |           ~~~~~~~~~~~~~~^~
towns.cpp:107:21: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  107 |     int t=ok[x].size();
      |           ~~~~~~~~~~^~
towns.cpp:109:16: warning: declaration of 'a' shadows a previous local [-Wshadow]
  109 |     vector<pi> a,b;
      |                ^
towns.cpp:65:15: note: shadowed declaration is here
   65 |   vector<int> a(n), b(n), c(n);
      |               ^
towns.cpp:109:18: warning: declaration of 'b' shadows a previous local [-Wshadow]
  109 |     vector<pi> a,b;
      |                  ^
towns.cpp:65:21: note: shadowed declaration is here
   65 |   vector<int> a(n), b(n), c(n);
      |                     ^
towns.cpp:112:21: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  112 |       int k = a.size();
      |               ~~~~~~^~
towns.cpp:113:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |       for (int i=0; i+1<a.size(); i+=2) {
      |                     ~~~^~~~~~~~~
towns.cpp:115:13: warning: declaration of 'x' shadows a previous local [-Wshadow]
  115 |         int x = d[a[i].f], y = d[a[i+1].f];
      |             ^
towns.cpp:101:12: note: shadowed declaration is here
  101 |   for(auto&x:st) {
      |            ^
towns.cpp:115:28: warning: declaration of 'y' shadows a previous local [-Wshadow]
  115 |         int x = d[a[i].f], y = d[a[i+1].f];
      |                            ^
towns.cpp:103:9: note: shadowed declaration is here
  103 |     int y=b[s]-x;
      |         ^
towns.cpp:131:11: warning: declaration of 'x' shadows a previous local [-Wshadow]
  131 |       int x = d[u], y = d[v];
      |           ^
towns.cpp:101:12: note: shadowed declaration is here
  101 |   for(auto&x:st) {
      |            ^
towns.cpp:131:21: warning: declaration of 'y' shadows a previous local [-Wshadow]
  131 |       int x = d[u], y = d[v];
      |                     ^
towns.cpp:103:9: note: shadowed declaration is here
  103 |     int y=b[s]-x;
      |         ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 340 KB Output is correct
2 Correct 9 ms 340 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 12 ms 340 KB Output is correct
5 Correct 12 ms 340 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 360 KB Output is correct
2 Correct 9 ms 340 KB Output is correct
3 Correct 12 ms 340 KB Output is correct
4 Correct 12 ms 340 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 340 KB Output is correct
2 Correct 12 ms 352 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 12 ms 356 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 340 KB Output is correct

Subtask #5
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 340 KB Output is correct
2 Correct 12 ms 860 KB Output is correct
3 Correct 12 ms 852 KB Output is correct

Subtask #6
0 / 39.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 212 KB Output isn't correct
2 Halted 0 ms 0 KB -