Submission #720618

#	Time	Username	Problem	Language	Result	Execution time	Memory
720618		bin9638	Connecting Supertrees (IOI20_supertrees)	C++17	100 / 100	196 ms	24236 KiB

supertrees

#include <bits/stdc++.h>

#ifndef SKY
#include "supertrees.h"
#endif // SKY

using namespace std;

#define N 1010
#define ll long long
#define fs first
#define sc second
#define ii pair<int,int>
#define pb push_back

int n,ktr[N];

#ifdef SKY
void build(vector<vector<int>>kq)
{
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)cout<<kq[i][j]<<" ";cout<<endl;
    }
}
#endif // SKY

struct DSU
{
    int lab[N];
    vector<int>lis[N];

    void init()
    {
        memset(lab,-1,sizeof(lab));
        for(int i=0;i<n;i++)
            lis[i].pb(i);
    }

    int root(int u)
    {
        if(lab[u]<0)
            return u;
        return(lab[u]=root(lab[u]));
    }

    bool update(int u,int v)
    {
        if((u=root(u))==(v=root(v)))
            return 0;
        if(lab[u]>lab[v])
            swap(u,v);
        lab[u]+=lab[v];
        lab[v]=u;
        for(auto x:lis[v])
            lis[u].pb(x);
        return 1;
    }
}T,D;

int construct(vector<vector<int>> p)
{
    n=p[0].size();
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            if(p[i][j]==3)
                return 0;
    T.init();
    D.init();
    vector<vector<int>>kq;
    kq.resize(n,vector<int>(n,0));
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            if(p[i][j]==1)
            {
                if(T.update(i,j)&&D.update(i,j))
                    kq[i][j]=kq[j][i]=1;
            }
    for(int i=0;i<n;i++)
    {
        D.lis[i].clear();
        if(D.root(i)==i)
            D.lis[i].pb(i);
    }
     for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            if(p[i][j]==2)
            {
                D.update(i,j);
            }
    //for(int i=0;i<n;i++)cout<<T.root(i)<<" "<<D.root(i)<<endl;
    for(int i=0;i<n;i++)
        if(D.root(i)==i&&D.lis[i].size()>1)
        {
            vector<int>s=D.lis[i];
            if(s.size()==2)
                return 0;
            kq[s[0]][s.back()]=kq[s.back()][s[0]]=1;
            for(int i=1;i<s.size();i++)
                kq[s[i-1]][s[i]]=kq[s[i]][s[i-1]]=1;
        }
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
        {
            if(p[i][j]==0)
            {
                if(D.root(i)==D.root(j))
                    return 0;
            }
            if(p[i][j]==1)
            {
                if(!(T.root(i)==T.root(j)&&D.root(i)==D.root(j)))
                    return 0;
            }
            if(p[i][j]==2)
            {
                if(!(T.root(i)!=T.root(j)&&D.root(i)==D.root(j)))
                    return 0;
            }
        }
    build(kq);
    return 1;
}

#ifdef SKY
int main()
{
    freopen("A.inp","r",stdin);
    freopen("A.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    int n;
    cin>>n;
    vector<vector<int>>p;
    p.resize(n,vector<int>(n,0));
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            cin>>p[i][j];
    cout<<construct(p);
    return 0;
}
#endif

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:99:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |             for(int i=1;i<s.size();i++)
      |                         ~^~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 21 / 21
• Subtask 6: 4 / 4