#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define ll long long
ll mod=1000000007;
int inf=1000000007;
ll infl=1000000000000000007;
const int N=1007;
/*void build(vector<vector<int>>r)
{
int n=sz(r);
for(int i=0;i<n;i++)
{
for(int j=0;j<n;j++) cout<<r[i][j]<<" ";
cout<<endl;
}
}*/
bool odw[N];
int odw1[N];
vector<int>V,V1;
int G[N][N];
int n,c;
bool ok=1;
void dfs(int v)
{
odw[v]=1;
for(auto u:V) if(G[v][u]==0) ok=0;
V.pb(v);
for(int i=0;i<n;i++) if(G[v][i]>0&&!odw[i]) dfs(i);
}
void dfs1(int v)
{
odw1[v]=c;
for(auto u:V1) if(G[v][u]!=1) ok=0;
V1.pb(v);
for(int i=0;i<n;i++) if(G[v][i]==1&&!odw1[i]) dfs1(i);
}
int construct(vector<vector<int>>p)
{
n=sz(p);
for(int i=0;i<n;i++) for(int j=0;j<n;j++) G[i][j]=p[i][j];
vector<vector<int>>b(n,vector<int>(n,0));
for(int i=0;i<n;i++)
{
if(odw[i]) continue;
V.clear();
dfs(i);
memset(odw1,0,sizeof odw1);
vector<int>cycle;
for(auto v:V)
{
if(odw1[v]) continue;
cycle.pb(v);
c++;
V1.clear();
dfs1(v);
for(auto a:V1)
{
for(auto b:V)
{
if(odw1[b]!=c&&G[a][b]!=2) ok=0;
}
}
for(int i=1;i<sz(V1);i++)
{
b[V1[i]][V1[i-1]]=1;
b[V1[i-1]][V1[i]]=1;
}
}
for(int i=0;i<sz(cycle);i++)
{
b[cycle[i]][cycle[(i+1)%n]]=1;
b[cycle[(i+1)%n]][cycle[i]]=1;
}
}
if(!ok) return 0;
build(b);
return 1;
}
/*int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cout<<construct({{1, 1, 2, 2}, {1, 1, 2, 2}, {2, 2, 1, 2}, {2, 2, 2, 1}});
return 0;
}*/
Compilation message
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:90:5: error: 'build' was not declared in this scope
90 | build(b);
| ^~~~~
