Submission #938938

#	Time	Username	Problem	Language	Result	Execution time	Memory
938938		AdamGS	Longest Trip (IOI23_longesttrip)	C++17	100 / 100	12 ms	952 KiB

longesttrip

#include "longesttrip.h"
#include<bits/stdc++.h>
using namespace std;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
vector<int>longest_trip(int n, int d) {
  vector<pair<int,int>>X, Y;
  vector<int>A, B;
  rep(i, n/2) if(are_connected({2*i}, {2*i+1})) X.pb({2*i, 2*i+1}); else Y.pb({2*i, 2*i+1});
  if(n%2==1) A.pb(n-1);
  for(auto i : X) {
    if(A.size()==0) {
      A.pb(i.st);
      A.pb(i.nd);
      continue;
    }
    if(B.size()==0) {
      B.pb(i.st);
      B.pb(i.nd);
      continue;
    }
    if(are_connected({A.back()}, {i.st})) {
      A.pb(i.st);
      A.pb(i.nd);
      continue;
    }
    if(are_connected({B.back()}, {i.st})) {
      B.pb(i.st);
      B.pb(i.nd);
      continue;
    }
    reverse(all(B));
    for(auto j : B) A.pb(j);
    B.clear();
    B.pb(i.st);
    B.pb(i.nd);
  }
  for(auto i : Y) {
    if(A.size()==0) {
      A.pb(i.st);
      B.pb(i.nd);
      continue;
    }
    if(!are_connected({A.back()}, {i.st})) swap(i.st, i.nd);
    A.pb(i.st);
    if(B.size()==0 || are_connected({B.back()}, {i.nd})) {
      B.pb(i.nd);
      continue;
    }
    reverse(all(B));
    for(auto j : B) A.pb(j);
    B.clear();
    B.pb(i.nd);
  }
  if(A.size()==n) return A;
  if(!are_connected(A, B)) {
    if(A.size()<B.size()) return B;
    return A;
  }
  if(are_connected({A.back()}, {B.back()})) {
    reverse(all(B));
    for(auto i : B) A.pb(i);
    return A;
  }
  if(are_connected({A.back()}, {B[0]})) {
    for(auto i : B) A.pb(i);
    return A;
  }
  if(are_connected({A[0]}, {B.back()})) {
    for(auto i : A) B.pb(i);
    return B;
  }
  if(are_connected({A[0]}, {B[0]})) {
    reverse(all(A));
    for(auto i : B) A.pb(i);
    return A;
  }
  int po=0, ko=A.size()-1;
  while(po<ko) {
    int sr=(po+ko)/2;
    vector<int>C;
    rep(i, sr+1) C.pb(A[i]);
    if(are_connected(C, B)) ko=sr; else po=sr+1;
  }
  int x=po;
  po=0; ko=B.size()-1;
  while(po<ko) {
    int sr=(po+ko)/2;
    vector<int>C, D;
    rep(i, x+1) C.pb(A[i]);
    rep(i, sr+1) D.pb(B[i]);
    if(are_connected(C, D)) ko=sr; else po=sr+1;
  }
  int y=po;
  vector<int>ans;
  rep(i, A.size()) ans.pb(A[(x+i+1)%A.size()]);
  rep(i, B.size()) ans.pb(B[(y+i)%B.size()]);
  return ans;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:58:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   58 |   if(A.size()==n) return A;
      |      ~~~~~~~~^~~
longesttrip.cpp:4:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    4 | #define rep(a, b) for(int a = 0; a < (b); ++a)
      |                                    ^
longesttrip.cpp:99:3: note: in expansion of macro 'rep'
   99 |   rep(i, A.size()) ans.pb(A[(x+i+1)%A.size()]);
      |   ^~~
longesttrip.cpp:4:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    4 | #define rep(a, b) for(int a = 0; a < (b); ++a)
      |                                    ^
longesttrip.cpp:100:3: note: in expansion of macro 'rep'
  100 |   rep(i, B.size()) ans.pb(B[(y+i)%B.size()]);
      |   ^~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 60 / 60