/*
In the name of Allah
made by: Ahmed_Solyman
*/
#include <bits/stdc++.h>
#include <ext/rope>
using namespace std;
using namespace __gnu_cxx;
#pragma GCC optimize("-Ofast")
#pragma GCC optimize("-O1")
//-------------------------------------------------------------//
typedef long long ll;
typedef unsigned long long ull;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define PI acos(-1)
#define lb lower_bound
#define ub upper_bound
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define sum_to(n) (n*(n+1))/2
#define pb push_back
#define pf push_front
#define fil(arr,x) memset(arr,x,sizeof(arr))
#define endl '\n'
const ll mod=1e9+7;
int dx[8]={0,1,0,-1,1,1,-1,-1};
int dy[8]={1,0,-1,0,1,-1,-1,1};
//-------------------------------------------------------------//
ll lcm(ll a,ll b)
{
return (max(a,b)/__gcd(a,b))*min(a,b);
}
void person_bool(bool x)
{
cout<<(x?"YES":"NO")<<endl;
}
void build(vector<vector<int>>b);
struct DSU{
vector<int>P,sz;
void init(int n){
P.resize(n+5);
sz.assign(n+5,1);
for(int i=0;i<n+5;i++)P[i]=i;
}
int find(int node){
if(P[node]==node)return node;
return P[node]=find(P[node]);
}
bool unite(int a,int b){
int p1=find(a);
int p2=find(b);
if(p1==p2){
return 0;
}
if(sz[p1]>sz[p2]){
swap(p1,p2);
}
P[p1]=p2;
sz[p2]+=sz[p1];
return 1;
}
}dsu;
int construct(vector<vector<int>> p){
int n=p.size();
dsu.init(n);
vector<vector<int>>b(n,vector<int>(n));
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
if(p[i][j])dsu.unite(i,j);
}
}
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
if(!p[i][j] && dsu.find(i)==dsu.find(j)){
return 0;
}
}
}
vector<int>v[n];
for(int i=0;i<n;i++)v[dsu.find(i)].push_back(i);
vector<vector<int>>b(n,vector<int>(n));
for(int i=0;i<n;i++){
for(int j=1;j<v[i].size();j++){
b[v[i][j-1]][v[i][j]]=1;
b[v[i][j]][v[i][j-1]]=1;
}
}
build(b);
return 1;
}
Compilation message
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:82:24: error: redeclaration of 'std::vector<std::vector<int> > b'
82 | vector<vector<int>>b(n,vector<int>(n));
| ^
supertrees.cpp:67:24: note: 'std::vector<std::vector<int> > b' previously declared here
67 | vector<vector<int>>b(n,vector<int>(n));
| ^
supertrees.cpp:84:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
84 | for(int j=1;j<v[i].size();j++){
| ~^~~~~~~~~~~~
