J - Xingqiu's Joke

传送门

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#include <bits/stdc++.h>
#define endl '\n'
#define IOS ios::sync_with_stdio(false);
using namespace std;

typedef long long ll;
const int inf = 0x3f3f3f3f;
ll T, a, b;
map<pair<int, int>, int> vis;
vector<int> v;

ll dfs(ll a, ll b)
{
	pair<int, int> p;
	p.first = a, p.second = b;
	if (a == 1 || b == 1)
		return vis[p] = 0;
	if (vis.count(p))
		return vis[p];
	ll ans = a - 1;
	if (b - a == 1)
		return vis[p] = a - 1;
	int cha = b - a;
	for (int i = 0; i < v.size(); ++i)
	{
		if (cha % v[i] == 0)
		{
			int x = a % v[i], y = v[i] - a % v[i];
			ans = min(ans, 1 + x + dfs((a - x) / v[i], (b - x) / v[i]));
			ans = min(ans, 1 + y + dfs((a + y) / v[i], (b + y) / v[i]));
		}
	}
	vis[p] = ans;
	return vis[p];
}

int main()
{
	//IOS; cin.tie(0), cout.tie(0);
	cin >> T;
	while (T--)
	{
		vis.clear(), v.clear();
		cin >> a >> b;
		if (b < a)
			swap(a, b);
		ll cha = b - a;
		for (int i = 2; i <= sqrt(cha); ++i)
		{
			if (cha % i == 0)
			{
				v.push_back(i);
				while (cha % i == 0)
					cha /= i;
			}
		}
		if (cha != 1)
			v.push_back(cha);
		cout << dfs(a, b) << endl;
	}

	return 0;
}