Submission #814621

#	Time	Username	Problem	Language	Result	Execution time	Memory
814621		LIF	Thousands Islands (IOI22_islands)	C++17	9.10 / 100	40 ms	11956 KiB

islands

#include "islands.h"
#include<bits/stdc++.h>
#include <variant>
#include <vector>
using namespace std;
int ind[300005];
int ph[1005][1005];
vector<int> vv[300005];
bool can[300005];
void dfs(int now,int fa)
{
  can[now] = true;
  for(int i=0;i<vv[now].size();i++)
  {
    int go = vv[now][i];
    if(can[go] == false)dfs(go,now);
  }
}
std::variant<bool, std::vector<int>> find_journey(
    int N, int M, std::vector<int> U, std::vector<int> V) {
  for(int i=0;i<M;i++)
  {
    vv[U[i]].push_back(V[i]);
    ind[V[i]]++;
  }
  dfs(0,-1);
  if(ind[0] >= 2)return true;
  for(int i=1;i<N;i++)
  {
     if(ind[i] >= 3 && can[i] == true)return true; 
  } 
 	/*
  if (N == 4) {
    return std::vector<int>({0, 1, 2, 4, 0, 3, 2, 1, 4, 3});
  }
  return false;*/
  return false;
}

Compilation message (stderr)

islands.cpp: In function 'void dfs(int, int)':
islands.cpp:13:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |   for(int i=0;i<vv[now].size();i++)
      |               ~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 7.35 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45