Submission #312002

#	Time	Username	Problem	Language	Result	Execution time	Memory
312002		Blerargh	Connecting Supertrees (IOI20_supertrees)	C++17	Compilation error	0 ms	0 KiB

supertrees

#include <bits/stdc++.h>
using namespace std;

#define FOR(i,a,b) for (int i=(a); i<=(b); i++)
#define ROF(i,a,b) for (int i=(a); i>=(b); i--)
#define gay cout << "gay";

bool visited[1005];
int parent[1005], n;
vector<vector<int> > answer, pp;

int fp(int a){
    if (a == parent[a]) return a;
    else return parent[a] = fp(parent[a]);
}

bool join(int a, int b){
    int pa = fp(a);
    int pb = fp(b);
    if (pa!=pb) {
        parent[b] = a;
        return 1;
    } else return 0;
}

void dfs(int u, int start){
	visited[fp(u)] = 1;
	bool check=0;
	FOR(i,0,n-1){
		if (pp[u][i] != 2) continue;
		else if (!visited[fp(i)]) {
			answer[u][i] = answer[i][u] = 1;
			dfs(i, start);
			check = 1;
		}
	}
	if (!check) answer[u][start] = answer[start][u] = 1;
	return;
}

vector<vector<int> > chk;
bool visiting[1005];

void dfscheck(int u, int start){
	//cout << u << '\n';
	visiting[u] = 1;
	chk[start][u]++;
	FOR(i,0,n-1){
		if (!answer[u][i]) continue;
		if (!visiting[i]) dfscheck(i, start);
	}
	visiting[u] = 0;
	return;
}

bool test(){
	FOR(i,0,n-1){
		visiting[i] = 0;
		vector<int> row;
		row.resize(n);
		chk.push_back(row);
		FOR(j,0,n-1) chk[i][j] = 0;
	}
	
	FOR(i,0,n-1){
		dfscheck(i,i);
	}
	
	/*
	FOR(i,0,n-1){
		FOR(j,0,n-1){
			cout << chk[i][j] << " ";
		}
		cout << '\n';
	}
	*/
	
	if (chk == pp) return 1;
	else return 0;
}

int construct(vector<vector<int> > p){
	pp = p;
	n = p.size();
	
	FOR(i,0,n-1){
		parent[i] = i;
		visited[i] = 0;
	}
	
	answer.clear();
	FOR(i,0,n-1){
		vector<int> row;
		row.resize(n);
		answer.push_back(row);
	}
	
    bool imposs=0;
    FOR(i,0,n-1) {
        FOR(j,0,n-1){
            if (i==j && p[i][j] != 1) imposs=1;
            if (p[i][j] != p[j][i]) imposs=1;
            if (p[i][j] == 3) imposs=1;

            if (imposs) break;

            if (p[i][j] == 1 && join(i,j)) answer[i][j] = answer[j][i] = 1;
        }
        if (imposs) break;
    }
    
    if (imposs) return 0;
    
    FOR(i,0,n-1){
    	if (!visited[fp(i)]) dfs(i,i);
    }
    
    if (test()) {
    	build(answer);
    	return 1;
    } else return 0;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:119:6: error: 'build' was not declared in this scope
  119 |      build(answer);
      |      ^~~~~