C. Digital Logarithm

https://codeforces.com/contest/1728/problem/C

模拟题

inline void solve() {
	int n;
	cin >> n;

	multiset<int> a, b;
	for (int i = 0; i < n; ++i) {
		int t;
		cin >> t;
		a.insert(t);
	}
	for (int i = 0; i < n; ++i) {
		int t;
		cin >> t;
		b.insert(t);
	}

	list<int> ls;
	for (auto x : a) {
		if (b.find(x) != b.end()) {
			b.erase(b.find(x));
			ls.push_back(x);
		}
		
	}
	while (!ls.empty()) {
		a.erase(a.find(ls.back()));
		ls.pop_back();
	}

	auto getBits = [](int x) {
		int res = 0;
		while (x) {
			x /= 10;
			res ++;
		}
		return res;
	};

	map<int, multiset<int>> ma, mb;
	for (auto x : a) {
		int t = getBits(x);
		ma[t].insert(x);
	}
	for (auto x : b) {
		int t = getBits(x);
		mb[t].insert(x);
	}

	int ans = 0;
	auto cal = [&ls, &getBits, &ans](multiset<int>& l, multiset<int>& r, map<int, multiset<int>>& ml, map<int, multiset<int>>& mr) {
		for (auto x : l) {
			if (x < 2 || x > 9) {
				continue;
			}
			if (!mr[x].empty()) {
				auto f = *mr[x].begin();
				mr[x].erase(mr[x].begin());
				ls.push_back(x);
				r.erase(r.find(f));
			}
		}
		ans += ls.size();
		while (!ls.empty()) {
			auto x = ls.back();
			l.erase(l.find(x));
			ls.pop_back();
			auto t = getBits(x);
			ml[t].erase(ml[t].find(x));
		}
	};
	cal(a, b, ma, mb);
	cal(b, a, mb, ma);

	for (int i = 2; i < 10; ++i) {
		int maxn = max(ma[i].size(), mb[i].size());
		ans += 2 * maxn;
	}
	ans += ma[1].size() + mb[1].size();
	ans -= ma[1].count(1) + mb[1].count(1);

	cout << ans << '\n';
}