Submission #347017

#	Time	Username	Problem	Language	Result	Execution time	Memory
347017		Dilshod_Imomov	Connecting Supertrees (IOI20_supertrees)	C++17	Compilation error	0 ms	0 KiB

supertrees

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

using namespace std;

const int N = 1e3 + 7;

vector < int > adj[N], visited(N);

void dfs( int v ) {
    visited[v] = 1;
    for ( auto u: adj[v] ) {
        if ( !visited[u] ) {
            dfs(u);
        }
    }
}

int construct(std::vector<std::vector<int>> p) {
	int n = p.size();
	std::vector<std::vector<int>> answer;
	for (int i = 0; i < n; i++) {
		std::vector<int> row;
		row.resize(n);
		answer.push_back(row);
	}
	for ( int i = 0; i < n; i++ ) {
        for ( int j = 0; j < n; j++ ) {
            if ( i == j ) {
                continue;
            }
            if ( p[i][j] == 1 ) {
                adj[i].push_back(j);

            }
        }
	}
	vector < int > comp, used(n + 7);
	for ( int i = 0; i < n; i++ ) {
        if ( visited[i] ) {
            continue;
        }
      	first[i] = i;
        for ( auto j: adj[i] ) {
        	first[j] = i;
        	visited[j] = 1;
        }
        comp.push_back(i);
	}
    for ( int i = 0; i < n; i++ ) {
        if ( used[i] ) {
            continue;
        }
        used[i] = i + 1;
        for ( auto j: adj[i] ) {
            answer[i][j] = 1;
            used[j] = i + 1;
            answer[j][i] = 1;
        }
    }
    for ( int j = 0; j < n; j++ ) {
    	for ( int i = 0; i < n; i++ ) {
    		if ( p[i][j] == 1 && first[i] != first[j] ) {
    			return 0;
    		}
    	}
    }
    int sz = comp.size();
    used = vector < int > (n + 7);
    for ( int i = 0; i < sz; i++ ) {
        vector < int > vc = { comp[i] };
        if ( used[ comp[i] ] ) {
            continue;
        }
        used[ comp[i] ] = i + 1;
        for ( int j = 0; j < sz; j++ ) {
            if ( i != j && p[ comp[i] ][ comp[j] ] == 2 ) {
                vc.push_back(comp[j]);
                used[ comp[j] ] = i + 1;
            }
        }
        int szz = vc.size();
        for ( int i = 0; i < szz - 1; i++ ) {
            answer[vc[i]][vc[i + 1]] = 1;
            answer[ vc[i + 1] ][ vc[i] ] = 1;
        }
        if ( szz > 1 ) {
            answer[ vc[szz - 1] ][ vc[0] ] = 1;
            answer[ vc[ 0 ] ][ vc[szz - 1] ] = 1;
        }
    }
	build(answer);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:43:8: error: 'first' was not declared in this scope
   43 |        first[i] = i;
      |        ^~~~~
supertrees.cpp:63:28: error: 'first' was not declared in this scope
   63 |       if ( p[i][j] == 1 && first[i] != first[j] ) {
      |                            ^~~~~