Submission #554379

#	Time	Username	Problem	Language	Result	Execution time	Memory
554379		n0sk1ll	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	231 ms	24268 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>

using namespace std;

int up[1003];
vector<int> chain[1003];
vector<int> head;
vector<int> kompofheads[1003];

int Up(int x)
{
    if (up[x]<0) return x;
    return up[x]=Up(up[x]);
}

void dsu(int a, int b)
{
    a=Up(a),b=Up(b);
    if (a==b) return;
    up[a]=b;
}

vector<vector<int>> ans;

void add(int i, int j)
{
    ans[i][j]=1,ans[j][i]=1;
}

int construct(vector<vector<int>> p)
{
	int n = p.size();

	for (int i=0;i<n;i++)
    {
        vector<int> pom(n,0);
        ans.push_back(pom);
    }

	for (int i=0;i<n;i++)
        if (p[i][i]!=1) return 0;

	for (int i=0;i<n;i++)
        for (int j=0;j<n;j++)
            if (p[i][j]==3) return 0;

    for (int i=0;i<n;i++) up[i]=-1;
    for (int i=0;i<n;i++)
        for (int j=0;j<n;j++)
            if (p[i][j]==1) dsu(i,j);

    for (int i=0;i<n;i++)
        for (int j=0;j<n;j++)
            if (Up(i)==Up(j) && p[i][j]!=1) return 0;

    for (int i=0;i<n;i++) chain[Up(i)].push_back(i);
    for (int i=0;i<n;i++) if (up[i]<0) head.push_back(i);

    for (int i=0;i<n;i++)
        for (int j=0;j<n;j++)
            if (p[i][j]) dsu(i,j);

    for (int i=0;i<n;i++)
        for (int j=0;j<n;j++)
            if (Up(i)==Up(j) && !p[i][j]) return 0;

    for (int i=0;i<head.size();i++)
        kompofheads[Up(head[i])].push_back(head[i]);

    for (int i=0;i<n;i++)
    {
        if (kompofheads[i].size()==2) return 0;
        if (kompofheads[i].size()>2)
        {
            for (int j=1;j<kompofheads[i].size();j++) add(kompofheads[i][j-1],kompofheads[i][j]);
            add(kompofheads[i].front(),kompofheads[i].back());
        }
    }

    for (int i=0;i<n;i++)
        for (int j=1;j<chain[i].size();j++)
            add(chain[i][j-1],chain[i][j]);

	build(ans);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:68:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |     for (int i=0;i<head.size();i++)
      |                  ~^~~~~~~~~~~~
supertrees.cpp:76:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |             for (int j=1;j<kompofheads[i].size();j++) add(kompofheads[i][j-1],kompofheads[i][j]);
      |                          ~^~~~~~~~~~~~~~~~~~~~~~
supertrees.cpp:82:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |         for (int j=1;j<chain[i].size();j++)
      |                      ~^~~~~~~~~~~~~~~~
supertrees.cpp:81:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   81 |     for (int i=0;i<n;i++)
      |     ^~~
supertrees.cpp:85:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   85 |  build(ans);
      |  ^~~~~

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