Submission #487746

#	Time	Username	Problem	Language	Result	Execution time	Memory
487746		ala2	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	12 ms	23756 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[1001000];
int construct(vector<vector<int>> p) {
	int n = p.size();
	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;
    } int bb=0;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            if(p[i][j])
            {
                //cout<<"                "<<i<<" " <<j<<"  "<<root(i)<<"  "<<root(j)<<" ";
                unit(i,j);
               // cout<<root(i)<<endl;

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

      //      cout<<v[i].size()<<endl;
      if(v[i].size()==2)
        bb=1;
        for(int j=0;j<v[i].size()-1;j++)
        {

            int x=v[i][j];
            int y=v[i][j+1];
    //        cout<<x<<" ";
          //  if(j==v[i].size()-1)
            //    cout<<y<<" ";
            if(i==v[i].size()-2)
            {
                answer[y][0]=1;
                answer[0][y]=1;
            }
            answer[x][y]=1;
            answer[y][x]=1;
        }

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

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:82:7: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   82 |       if(v[i].size()==2)
      |       ^~
supertrees.cpp:84:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   84 |         for(int j=0;j<v[i].size()-1;j++)
      |         ^~~
supertrees.cpp:84:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |         for(int j=0;j<v[i].size()-1;j++)
      |                     ~^~~~~~~~~~~~~~
supertrees.cpp:92:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |             if(i==v[i].size()-2)
      |                ~^~~~~~~~~~~~~~~
supertrees.cpp:102:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  102 |     if(bb)
      |     ^~
supertrees.cpp:104:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  104 |  build(answer);
      |  ^~~~~

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