Submission #1065037

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065037		kkkkkkkk	Connecting Supertrees (IOI20_supertrees)	C++14	21 / 100	158 ms	24144 KiB

supertrees

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

using namespace std;

int parent[1005], sz[1005];

int Find(int x) {
    if (x==parent[x])
        return x;
    return parent[x]=Find(parent[x]);
}

void Union(int a, int b) {
    a=Find(a), b=Find(b);
    if (a==b) return;
    if (sz[a]<sz[b])
        swap(a, b);
    sz[a]+=sz[b];
    parent[b]=a;
}

int construct(vector<vector<int> > paths) {
    int n=paths.size();
    vector<vector<int> > a=paths;
    for (int i=0;i<n;i++)
        sz[i]=1, parent[i]=i;
    for (int i=0;i<n;i++)
        for (int j=0;j<n;j++)
            a[i][j]=0;
    bool vtor_subtask=true;
    for (int i=0;i<n;i++) {
        for (int j=i+1;j<n;j++) {
            if (paths[i][j]) Union(i, j);
            if (paths[i][j]==2) vtor_subtask=false;
        }
    }
    vector<int> gr[n];
    for (int i=0;i<n;i++) {
        int lider=Find(i);
        gr[lider].push_back(i);
    }
    for (int i=0;i<n;i++) {
        if (gr[i].size()) {
            for (auto x:gr[i])
                for (auto y:gr[i])
                    if (!paths[x][y])
                        return 0;
            if (vtor_subtask) {
                int x=gr[i][0];
                for (auto y:gr[i])
                    if (x!=y) a[x][y]=1, a[y][x]=1;
            }
            else {
                int x=gr[i][0], y=gr[i][gr[i].size()-1];
                for (int j=0;j<gr[i].size()-1;j++)
                    a[gr[i][j]][gr[i][j+1]]=1, a[gr[i][j+1]][gr[i][j]]=1;
                a[x][y]=1, a[y][x]=1;
            }
        }
    }
    build(a);
    return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:56:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |                 for (int j=0;j<gr[i].size()-1;j++)
      |                              ~^~~~~~~~~~~~~~~

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