#include <bits/stdc++.h>
using namespace std;

const int N=5e3+9;
int n,m,p;
int fa[N];

void merge(int a,int b){
	fa[find(a)]=find(b);
	return;
}

int find(int x){
	if(fa[x]!=x){
		fa[x]=find(fa[x])
	}
	return fa[x];
}

int main(){
	cin >>n>>m>>p;
	for(int i=1;i<=n;i++){
		fa[i]=i;
	}
	for(int i=1;i<=m;i++){
		int a,b;
		cin >>a>>b;
		merge(a,b);
	}
	for(int i=1;i<=p;i++){
		int a,b;
		cin >>a>>b;
		if(find(a)==find(b)){
			cout <<"Yes"<<endl;
		}
		else cout <<"No"<<endl;
	}
	return 0;
}

酱紫错的

/tmp/compiler_909hj7f6/src: 在函数‘void merge(int, int)’中: /tmp/compiler_909hj7f6/src:9:11: 错误：对‘find(int&)’的调用没有匹配的函数 9 | fa[find(a)]=find(b); | ^ In file included from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/locale_facets.h:48, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/basic_ios.h:37, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/ios:44, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/istream:38, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/sstream:38, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/complex:45, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/ccomplex:39, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54, from /tmp/compiler_909hj7f6/src:1: /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/streambuf_iterator.h:373:5: 附注：candidate: ‘template typename __gnu_cxx::__enable_if<std::__is_char<_CharT2>::__value, std::istreambuf_iterator<_CharT> >::__type std::find(std::istreambuf_iterator<_CharT>, std::istreambuf_iterator<_CharT>, const _CharT2&)’ 373 | find(istreambuf_iterator<_CharT> __first, | ^~~~ /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/streambuf_iterator.h:373:5: 附注： template argument deduction/substitution failed: /tmp/compiler_909hj7f6/src:9:11: 附注： mismatched types ‘std::istreambuf_iterator<_CharT>’ and ‘int’ 9 | fa[find(a)]=find(b); | ^ In file included from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/algorithm:62, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:65, from /tmp/compiler_909hj7f6/src:1: /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/stl_algo.h:3930:5: 附注：candidate: ‘template<class _IIter, class _Tp> _IIter std::find(_IIter, _IIter, const _Tp&)’ 3930 | find(_InputIterator __first, _InputIterator __last, | ^~~~ /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/stl_algo.h:3930:5: 附注： template argument deduction/substitution failed: /tmp/compiler_909hj7f6/src:9:11: 附注： 备选需要 3 实参，但提供了 1 个 9 | fa[find(a)]=find(b); | ^ /tmp/compiler_909hj7f6/src:9:20: 错误：对‘find(int&)’的调用没有匹配的函数 9 | fa[find(a)]=find(b); | ^ In file included from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/locale_facets.h:48, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/basic_ios.h:37, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/ios:44, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/istream:38, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/sstream:38, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/complex:45, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/ccomplex:39, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54, from /tmp/compiler_909hj7f6/src:1: /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/streambuf_iterator.h:373:5: 附注：candidate: ‘template typename __gnu_cxx::__enable_if<std::__is_char<_CharT2>::__value, std::istreambuf_iterator<_CharT> >::__type std::find(std::istreambuf_iterator<_CharT>, std::istreambuf_iterator<_CharT>, const _CharT2&)’ 373 | find(istreambuf_iterator<_CharT> __first, | ^~~~ /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/streambuf_iterator.h:373:5: 附注： template argument deduction/substitution failed: /tmp/compiler_909hj7f6/src:9:20: 附注： mismatched types ‘std::istreambuf_iterator<_CharT>’ and ‘int’ 9 | fa[find(a)]=find(b); | ^ In file included from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/algorithm:62, from /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:65, from /tmp/compiler_909hj7f6/src:1: /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/stl_algo.h:3930:5: 附注：candidate: ‘template<class _IIter, class _Tp> _IIter std::find(_IIter, _IIter, const _Tp&)’ 3930 | find(_InputIterator __first, _InputIterator __last, | ^~~~ /nix/store/bbmwawbq7wjb54fa35wr72alcm083d1f-luogu-gcc-9.3.0/include/c++/9.3.0/bits/stl_algo.h:3930:5: 附注： template argument deduction/substitution failed: /tmp/compiler_909hj7f6/src:9:20: 附注： 备选需要 3 实参，但提供了 1 个 9 | fa[find(a)]=find(b); | ^ /tmp/compiler_909hj7f6/src: 在函数‘int find(int)’中: /tmp/compiler_909hj7f6/src:15:20: 错误：expected ‘;’ before ‘}’ token 15 | fa[x]=find(fa[x]) | ^ | ; 16 | } | ~