1783E - Game of the Year - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 1;
int t, n, a[maxn], b[maxn], f[maxn];
vector<int> ans;
int main()
{
	scanf("%d", &t);
	while (t--) 
	{
		scanf("%d", &n);
		for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
		for (int i = 1; i <= n; i++) scanf("%d", &b[i]);
		memset(f, 0, sizeof(int)*(n + 1));
		for (int i = 1; i <= n; i++) if (a[i]>b[i]) f[b[i]]++, f[a[i]]--;
		for (int i = 1; i <= n; i++) f[i] += f[i - 1];
		ans.clear();
		for (int i = 1; i <= n; i++)
		{
			bool ok = true;
			for (int j = i; j <= n; j += i)
			{
				if (f[j] > 0) ok = false;
			}
			if (ok) ans.push_back(i);
		}
		printf("%d\n", (int)ans.size());
		for (int i = 0; i < ans.size(); i++)
			printf("%d ", ans[i]);
		printf("\n");
	}
	return 0;
}