Language: C++

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int par[100005],rank[100005];
void init(int n){
	for(int i=0;i<n;i++){
		par[i]=i;
		rank[i]=0;
	}
}
int find(int x){
	if(par[x]==x){
		return x;
	}else{
		return par[x]=find(par[x]);
	}
}
void unite(int x,int y){
	x=find(x);
	y=find(y);
	if(x==y) return;
	if(rank[x]<rank[y]){
		par[x]=y;
	}else{
		par[y]=x;
		if(rank[x]==rank[y]) rank[x]++;
	}
}
bool same(int x,int y){
	return find(x)==find(y);
}
int main(void){
	int n,m; cin>>n>>m;
	init(n);
	int ans=1;
	int a,b,c;
	for(int i=0;i<m;i++){
		cin>>a>>b>>c;
		unite(a,b);
	}
	for(int i=2;i<=n;i++){
		if(!same(1,i)){
			ans++;
			unite(1,i);
		}
	}
	cout<<ans<<endl;
	
}


Compiler output:
a.cc: In function 'void init(int)':
a.cc:8:17: error: reference to 'rank' is ambiguous
    8 |                 rank[i]=0;
      |                 ^~~~
In file included from /usr/include/c++/14/bits/stl_pair.h:60,
                 from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/type_traits:1437:12: note: candidates are: 'template<class> struct std::rank'
 1437 |     struct rank
      |            ^~~~
a.cc:4:17: note:                 'int rank [100005]'
    4 | int par[100005],rank[100005];
      |                 ^~~~
a.cc: In function 'void unite(int, int)':
a.cc:22:12: error: reference to 'rank' is ambiguous
   22 |         if(rank[x]<rank[y]){
      |            ^~~~
/usr/include/c++/14/type_traits:1437:12: note: candidates are: 'template<class> struct std::rank'
 1437 |     struct rank
      |            ^~~~
a.cc:4:17: note:                 'int rank [100005]'
    4 | int par[100005],rank[100005];
      |                 ^~~~
a.cc:22:20: error: reference to 'rank' is ambiguous
   22 |         if(rank[x]<rank[y]){
      |                    ^~~~
/usr/include/c++/14/type_traits:1437:12: note: candidates are: 'template<class> struct std::rank'
 1437 |     struct rank
      |            ^~~~
a.cc:4:17: note:                 'int rank [100005]'
    4 | int par[100005],rank[100005];
      |                 ^~~~
a.cc:26:20: error: reference to 'rank' is ambiguous
   26 |                 if(rank[x]==rank[y]) rank[x]++;
      |                    ^~~~
/usr/include/c++/14/type_traits:1437:12: note: candidates are: 'template<class> struct std::rank'
 1437 |     struct rank
      |            ^~~~
a.cc:4:17: note:                 'int rank [100005]'
    4 | int par[100005],rank[100005];
      |                 ^~~~
a.cc:26:29: error: reference to 'rank' is ambiguous
   26 |                 if(rank[x]==rank[y]) rank[x]++;
      |                             ^~~~
/usr/include/c++/14/type_traits:1437:12: note: candidates are: 'template<class> struct std::rank'
 1437 |     struct rank
      |            ^~~~
a.cc:4:17: note:                 'int rank [100005]'
    4 | int par[100005],rank[100005];
      |                 ^~~~
a.cc:26:38: error: reference to 'rank' is ambiguous
   26 |                 if(rank[x]==rank[y]) rank[x]++;
      |                                      ^~~~
/usr/include/c++/14/type_traits:1437:12: note: candidates are: 'template<class> struct std::rank'
 1437 |     struct rank
      |            ^~~~
a.cc:4:17: note:                 'int rank [100005]'
    4 | int par[100005],rank[100005];
      |                 ^~~~