A1063 Set Similarity [set]

#include<vector>
#include<iostream>
#include<algorithm>
#include<unordered_map>
#include<set>
#include<map>
using namespace std;
const int N=51;
set<int>st[N];
void compare(int a, int b)
{
	int differentnum=st[b].size(), samenum = 0;
	for (auto it : st[a])
	{
		if (st[b].find(it) != st[b].end())
		{
			samenum++;
		}
		else
			differentnum++;
	}
	printf("%.1f%%\n", samenum * 100.0 / differentnum); //输出两个百分号
}
int main()
{
	int n,m,temp; cin >> n;
	for (int i = 1; i <= n; i++)
	{
		cin >> m;
		for (int j = 0; j < m; j++)
		{
			cin >> temp;
			st[i].insert(temp);
		}
	}
	int queryn, a, b;
	cin >> queryn;
	for (int i = 0; i < queryn; i++)
	{
		cin >> a >> b;
		compare(a, b);
	}
}