Submission #487886

#	Time	Username	Problem	Language	Result	Execution time	Memory
487886		ala2	Connecting Supertrees (IOI20_supertrees)	C++14	96 / 100	232 ms	28072 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include<iostream>
using namespace std;
int pa[1001000];
int sz[1001000];
int root(int x)
{
    while(x!=pa[x])
    {
        pa[x]=pa[pa[x]];
        x=pa[x];
    }
    return x;
}

void unit(int x,int y)
{
    x=root(x);
    y=root(y);
    if(x==y)
        return ;
    if(sz[x]>sz[y])
    {
        sz[x]+=sz[y];
        pa[y]=x;
    }
    else
    {
        sz[y]+=sz[x];
        pa[x]=y;
    }
}

vector<int>v[1010];
int vi[1010];
int vis[5][1010][1010];
int construct(vector<vector<int>> p) {
	int n = p.size();
	int bb=0;
	vector<vector<int>> answer;
	for (int i = 0; i < n; i++) {
		vector<int> row;
		row.resize(n);
		answer.push_back(row);
	}
	for(int i=0;i<n;i++)
    {
        pa[i]=i;
        sz[i]=1;
    }
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            if(p[i][j]==1)
            {
                unit(i,j);
            }
        }
    }
    for(int i=0;i<n;i++)
    {
        v[root(i)].push_back(i);
    }
    for(int i=0;i<n;i++)
    {
        if(i!=root(i))
            continue;
        if(v[i].size()==1)
        {
            continue;
        }
        for(int j=0;j<v[i].size()-1;j++)
        {
            int x=v[i][j];
            int y=v[i][j+1];
            answer[x][y]=1;
            answer[y][x]=1;
        }
    }

    for(int i=0;i<n;i++)
    {
        if(i!=root(i))
            continue;
        int tow=0;
        vector<int>r;
        r.push_back(i);
        vi[root(i)]=1;
        for(int j=0;j<n;j++)
        {
            if(p[i][j]>=2&&!vi[root(j)])
            {
                if(p[i][j]==2)
                    tow=2;
                else tow=3;
                r.push_back(root(j));
                vi[root(j)]=1;
            }
        }
       // cout<<"           "<<r.size()<<endl;
       if(r.size()==1)
            continue;
        if(r.size()==2&&tow==2){
        bb=1;
        break;
        }
        if(r.size()<=3&&tow==3){
        bb=1;
        break;
        }

        for(int k=0;k<r.size()-1;k++)
        {
            int x=r[k];
            int y=r[k+1];
            answer[x][y]=1;
            answer[y][x]=1;
        }
        int ss=r.size()-1;
        answer[r[ss]][r[0]]=1;
        answer[r[0]][r[ss]]=1;
        if(tow>2){
        answer[r[0]][r[2]]=1;
        answer[r[2]][r[0]]=1;
        }
        for(int ii=0;ii<r.size();ii++)
        {
            for(int jj=0;jj<r.size();jj++)
            {
                if(ii==jj)
                    continue;
                vis[tow][r[ii]][r[jj]]=1;
                vis[tow][r[jj]][r[ii]]=1;
            }
        }

    }
    for(int i=0;i<n;i++)
    {
        answer[i][i]=0;
        for(int j=0;j<n;j++)
        {
            if(i==j)
                continue;
         //   cout<<vis[i][j]<<" ";
            if(p[i][j]>=2&&!vis[p[i][j]][root(i)][root(j)])
                bb=1;
            if(p[i][j]<2&&vis[p[i][j]][root(i)][root(j)])
                bb=1;
            if(p[i][j]==1&&root(i)!=root(j))
                bb=1;
            if(root(i)==root(j)&&p[i][j]!=1)
                bb=1;
            if(p[i][j]==0&&vis[3][root(i)][root(j)])
                bb=1;
                if(p[i][j]==0&&vis[2][root(i)][root(j)])
                bb=1;
        }

    }

    if(bb)
        return 0;
    else
    {
	build(answer);
	return 1;
    }

}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:74:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |         for(int j=0;j<v[i].size()-1;j++)
      |                     ~^~~~~~~~~~~~~~
supertrees.cpp:114:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  114 |         for(int k=0;k<r.size()-1;k++)
      |                     ~^~~~~~~~~~~
supertrees.cpp:128:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  128 |         for(int ii=0;ii<r.size();ii++)
      |                      ~~^~~~~~~~~
supertrees.cpp:130:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  130 |             for(int jj=0;jj<r.size();jj++)
      |                          ~~^~~~~~~~~
supertrees.cpp:156:13: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  156 |             if(p[i][j]==0&&vis[3][root(i)][root(j)])
      |             ^~
supertrees.cpp:158:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  158 |                 if(p[i][j]==0&&vis[2][root(i)][root(j)])
      |                 ^~

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