Submission #812537

#	Time	Username	Problem	Language	Result	Execution time	Memory
812537		andrei_boaca	Thousands Islands (IOI22_islands)	C++17	14.10 / 100	66 ms	36172 KiB

islands

#include "islands.h"

#include <variant>
#include <vector>
//#include <bits/stdc++.h>
//#include "grader.cpp"
using namespace std;
struct date
{
    int nod,a,b;
};
vector<date> muchii[100005];
vector<int> c[1005][1005];
bool useedge[300005],usenod[300005];
int n,m;
bool good=0;
void dfs(int nod)
{
    if(muchii[nod].size()>=3)
        good=1;
    usenod[nod]=1;
    for(date i:muchii[nod])
        if(!usenod[i.nod])
            dfs(i.nod);
}
std::variant<bool, std::vector<int>> find_journey(int N, int M, std::vector<int> U, std::vector<int> V)
{

    n=N;
    m=M;
    for(int i=0;i<m;i++)
    {
        int a=U[i];
        int b=V[i];
        c[a][b].push_back(i);
    }
    if(n==2)
    {
        if(c[0][1].size()>=2&&c[1][0].size()>=1)
        {
            int A=c[1][0][0];
            int B=c[0][1][0];
            int C=c[0][1][1];
            vector<int> sol={B,A,C,B,A,C};
            return sol;
        }
        return false;
    }
    for(int a=0;a<n;a++)
        for(int b=0;b<n;b++)
            if(a!=b)
            {
                for(int i=0;i<c[a][b].size()&&i<c[b][a].size();i++)
                {
                    int x=c[a][b][i];
                    int y=c[b][a][i];
                    muchii[a].push_back({b,x,y});
                }
            }
    if(muchii[0].size()>=2)
        return true;
    dfs(0);
    return good;
}

Compilation message (stderr)

islands.cpp: In function 'std::variant<bool, std::vector<int, std::allocator<int> > > find_journey(int, int, std::vector<int>, std::vector<int>)':
islands.cpp:53:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |                 for(int i=0;i<c[a][b].size()&&i<c[b][a].size();i++)
      |                             ~^~~~~~~~~~~~~~~
islands.cpp:53:48: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |                 for(int i=0;i<c[a][b].size()&&i<c[b][a].size();i++)
      |                                               ~^~~~~~~~~~~~~~~

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