OI-codes/S2OJ/1905/data/val.cpp

#include <bits/stdc++.h>
#include "testlib.h"
using namespace std;
const int N=1e5,M=2e5,K=4;
int fa[N+10];
int find(int x){
	if (fa[x]!=x) fa[x]=find(fa[x]);
	return fa[x];
}
void merge(int x, int y){
	fa[find(x)]=find(y);return;
}
int main(int argc, char** argv){
	registerValidation();
	int n=inf.readInt(1,N);inf.readSpace();
	int m=inf.readInt(1,M);inf.readChar('\n');
	map<pair<int,int>,int> mp;
	for (int i=1;i<=m;i++){
		int u=inf.readInt(1,n);inf.readSpace();
		int v=inf.readInt(1,n);inf.readChar('\n');
		ensuref(u!=v,"Graph can't contain loops");
		ensuref(!mp[{min(u,v),max(u,v)}],"Graph can't contain multiple edges between a pair of vertices");
		mp[{min(u,v),max(u,v)}]=1;merge(u,v);
	}for (int i=1;i<=n;i++){
		ensuref(find(i)==find(1),"Graph must be connected");
	}int q=inf.readInt(1,N);inf.readChar('\n');
	for (int i=1;i<=q;i++){
		int c=inf.readInt(1,m);map<int,int> mp;
		ensuref(c>=1&&c<=4,"Variable c must be >= 1 and <= 4");
		for (int j=1;j<=c;j++){
			inf.readSpace();int x=inf.readInt(1,m);
			ensuref(!mp[x],"Set can't contain same elements");
			mp[x]=1;
		}inf.readChar('\n');
	}inf.readEof();return 0;
}