Submission #746083

#	Time	Username	Problem	Language	Result	Execution time	Memory
746083		JakobZorz	Connecting Supertrees (IOI20_supertrees)	C++14	56 / 100	230 ms	28076 KiB

supertrees

#include "supertrees.h"
#include <vector>
using namespace std;

vector<vector<int>> answer;
int group_ids[1000];
vector<int> groups[1000];
vector<vector<int>> p;
int num_groups;

void connect(int a, int b){
    answer[a][b]=1;
    answer[b][a]=1;
}

void connect_group(int group_id){
    vector<int> group=groups[group_id];
    vector<bool> in_cycle(group.size(),false);
    vector<int> tree_ids(group.size(),-1);
    vector<int> trees[1000];
    
    int num_trees=0;
    for(int i=0;i<group.size();i++){
        if(tree_ids[i]!=-1)
            continue;
        tree_ids[i]=num_trees;
        trees[num_trees].push_back(i);
        for(int j=0;j<group.size();j++){
            if(i!=j&&p[group[i]][group[j]]==1){
                tree_ids[j]=num_trees;
                trees[num_trees].push_back(j);
                connect(group[i],group[j]);
            }
        }
        num_trees++;
    }
    
    for(int i=0;i<num_trees-1;i++)
        connect(group[trees[i][0]],group[trees[i+1][0]]);
    if(num_trees!=1)
        connect(group[trees[0][0]],group[trees[num_trees-1][0]]);
}

int construct(vector<vector<int>> p_) {
    p=p_;
    int n = p.size();
    answer=vector<vector<int>>(n,vector<int>(n,0));
    for(vector<int>& i:p)
        for(int j:i)
            if(j==3)
                return 0;
    for(int i=0;i<n;i++)
        group_ids[i]=-1;
    
    for(int i=0;i<n;i++){
        if(group_ids[i]!=-1)
            continue;
        
        group_ids[i]=num_groups;
        groups[num_groups].push_back(i);
        for(int j=i+1;j<n;j++){
            if(p[i][j]!=0){
                group_ids[j]=num_groups;
                groups[num_groups].push_back(j);
            }
        }
        num_groups++;
    }
    
    for(int i=0;i<n;i++)
        for(int j=i+1;j<n;j++){
            if(group_ids[i]!=group_ids[j]&&p[i][j]!=0)
                return 0;
            if(group_ids[i]==group_ids[j]&&p[i][j]==0)
                return 0;
        }
    
    for(int i=0;i<num_groups;i++)
        connect_group(i);
    
	build(answer);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'void connect_group(int)':
supertrees.cpp:23:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for(int i=0;i<group.size();i++){
      |                 ~^~~~~~~~~~~~~
supertrees.cpp:28:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         for(int j=0;j<group.size();j++){
      |                     ~^~~~~~~~~~~~~
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:78:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   78 |     for(int i=0;i<num_groups;i++)
      |     ^~~
supertrees.cpp:81:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   81 |  build(answer);
      |  ^~~~~

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