#include <bits/stdc++.h>
#include "supertrees.h"
//#define DEBUGGING
#ifdef DEBUGGING
#include "../debug.h"
#else
#define debug(x...) void(42)
#endif
using namespace std;
constexpr static int MXN = 1e3 + 5;
struct Node
{
int head, tail, size, nxt;
Node(int i) : head(i), tail(i), size(1), nxt(-1) {}
Node() : Node(-1) {}
};
Node node[MXN];
void merge(int a, int b);
int construct(vector<vector<int>> p)
{
int n = p.size();
vector<vector<int>> answer(n, vector<int>(n));
for (int i = 0; i < n; i++)
node[i] = Node(i);
for (int i = 0; i < n; i++)
for (int j = i+1; j < n; j++)
if (p[i][j] == 2 && node[i].head != node[j].head)
merge(node[i].head, node[j].head);
for (int i = 0; i < n; i++)
for (int j = i+1; j < n; j++)
if (!p[i][j] && node[i].head == node[j].head)
return 0;
for (int i = 0; i < n; i++)
{
if (node[i].head != i || node[i].size == 1)
continue;
debug(i, node[i].size);
if (node[i].size == 2)
return 0;
for (int j = i; node[j].nxt != -1; j = node[j].nxt)
{
debug(j, node[j].nxt);
answer[j][node[j].nxt] = answer[node[j].nxt][j] = 1;
}
debug(node[i].tail, i);
answer[i][node[i].tail] = answer[node[i].tail][i] = 1;
}
build(answer);
return 1;
}
void merge(int a, int b)
{
if (node[a].size < node[b].size) swap(a, b);
node[a].size += node[b].size;
node[node[a].tail].nxt = b;
node[a].tail = node[b].tail;
for (;b!=-1;b=node[b].nxt)
node[b].head = a;
}
