Submission #431378

#	Time	Username	Problem	Language	Result	Execution time	Memory
431378		MOUF_MAHMALAT	Connecting Supertrees (IOI20_supertrees)	C++14	19 / 100	304 ms	22104 KiB

supertrees

#include "supertrees.h"
#include<bits/stdc++.h>
using namespace std;
typedef int ll;
vector<vector<ll> >v,w;
vector<pair<ll,ll> >op;
ll n,p[1009],id[1009];
ll gp(ll z)
{
    if(p[z]==z)
        return z;
    return p[z]=gp(p[z]);
}
void mrg(ll x,ll y,ll k)
{
    if(w[y].size()>w[x].size())
        swap(x,y);
    p[y]=x;
    if(k==0)
        return;
    for(auto z:w[y])
        w[x].push_back(z);
    id[x]=id[y]=k;
}
int construct(vector<vector<int> > pp)
{
    n=pp.size();
    v.resize(n);
    w.resize(n);

    for(ll i=0; i<n; i++)
        v[i].resize(n);

    for(ll i=0; i<n; i++)
        p[i]=i,w[i].push_back(i);

    for(ll i=0; i<n; i++)
        for(ll j=0; j<n; j++)
        {
            if(pp[i][j]<2)
                continue;
            ll x=gp(i),y=gp(j);
            if(x==y)
                continue;
            if(id[x]*id[y]==6)
                return 0;
            mrg(x,y,pp[i][j]);
        }
    for(ll i=0; i<n; i++)
        if(p[i]==i)
        {
            if(id[i]==3)
            {
                if(w[i].size()<4)
                    return 0;
                for(ll j=0; j<w[i].size()-1; j++)
                    op.push_back({w[i][j],w[i][j+1]});
                op.push_back({w[i][0],w[i].back()});
                op.push_back({w[i][1],w[i].back()});
            }
            else if(id[i]==2)
            {
                if(w[i].size()<3)
                    return 0;
                for(ll j=0; j<w[i].size()-1; j++)
                    op.push_back({w[i][j],w[i][j+1]});
                op.push_back({w[i][0],w[i].back()});
            }
        }
    for(ll i=0; i<n; i++)
        for(ll j=0; j<n; j++)
        {
            if(pp[i][j]!=1||i==j)
                continue;
            ll x=gp(x),y=gp(y);
            if(w[x].size()>1&&w[y].size()>1)
                return 0;
            if(x==y)
                continue;
            mrg(x,y,0);
            op.push_back({i,j});
        }
    for(ll i=0; i<n; i++)
        for(ll j=0; j<n; j++)
        {
            if(pp[i][j])
                continue;
            ll x=gp(i),y=gp(j);
            if(x==y)
                return 0;
        }
    for(auto z:op)
        v[z.first][z.second]=v[z.second][z.first]=1;
    build(v);
    return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:56:30: warning: comparison of integer expressions of different signedness: 'll' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |                 for(ll j=0; j<w[i].size()-1; j++)
      |                             ~^~~~~~~~~~~~~~
supertrees.cpp:65:30: warning: comparison of integer expressions of different signedness: 'll' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |                 for(ll j=0; j<w[i].size()-1; j++)
      |                             ~^~~~~~~~~~~~~~
supertrees.cpp:12:16: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   12 |     return p[z]=gp(p[z]);
      |            ~~~~^~~~~~~~~
supertrees.cpp:75:24: note: 'y' was declared here
   75 |             ll x=gp(x),y=gp(y);
      |                        ^
supertrees.cpp:12:16: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   12 |     return p[z]=gp(p[z]);
      |            ~~~~^~~~~~~~~
supertrees.cpp:75:16: note: 'x' was declared here
   75 |             ll x=gp(x),y=gp(y);
      |                ^

• Subtask 1: 0 / 11
• Subtask 2: 0 / 10
• Subtask 3: 19 / 19
• Subtask 4: 0 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4