#include <bits/stdc++.h>
using namespace std;
#include "supertrees.h"
#include <vector>
int construct(std::vector<std::vector<int>> p) {
int n = p.size();
std::vector<std::vector<int>> ans (n, vector < int > (n));
vector < array < bool, 4 > > pt (n);
vector < pair < int, int > > dsu (n);
for (int i = 0; i < n; ++i) dsu[i].first = -1, dsu[i].second = 1;
for (int i = 0; i < n; ++i)
for (int j = i + 1; j < n; ++j)
if (p[i][j])
{
pt[i][p[i][j]] = true;
pt[j][p[i][j]] = true;
int ci = i, cj = j;
while (dsu[ci].first != -1) ci = dsu[ci].first;
while (dsu[cj].first != -1) cj = dsu[cj].first;
if (ci != cj)
{
if (dsu[ci].second < dsu[cj].second) swap (ci, cj);
dsu[cj].first = ci;
dsu[ci].second += dsu[cj].second;
}
}
map < int, array < set < int >, 4 > > m;
for (int i = 0; i < n; ++i)
{
int ci = i;
while (dsu[ci].first != -1) ci = dsu[ci].first;
for (int j = 0; j < 4; ++j) if (pt[i][j]) m[ci][j].insert (i);
}
for (auto &[xx, x] : m)
{
if (x[1].empty () && x[2].empty ()) continue;
int p = -1;
for (auto &y : x[1])
{
if (p >= 0) ans[p][y] = ans[y][p] = 1;
p = y;
}
if (x[2].empty ()) continue;
int pp = p;
int c = 0;
for (auto &y : x[2])
{
if (x[1].count (y)) continue;
++c;
if (p >= 0) ans[p][y] = ans[y][p] = 1;
p = y;
}
if (pp == -1) pp = *x[2].first ();
ans[p][pp] = ans[pp][p] = 1;
if (c < 2) return 0;
}
build (ans);
return 1;
}
Compilation message
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:54:32: error: 'std::array<std::set<int>, 4>::value_type' {aka 'class std::set<int>'} has no member named 'first'
54 | if (pp == -1) pp = *x[2].first ();
| ^~~~~
