#621101 (C++17) No.1282 Display Elements

• 問題: No.1282 Display Elements
• ユーザー: tkmst201
• 提出日時: 2021-02-22 11:59:23
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 67 ms / 2,000 ms
• コード長: 2,536 bytes
• コンパイル時間: 2,306 ms
• コンパイル使用メモリ: 210,348 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-09-21 10:48:28
• 合計ジャッジ時間: 3,791 ms
• ジャッジサーバーID （参考情報）: judge4 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 5,248 KB
testcase_01	AC	2 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	2 ms; 5,376 KB
testcase_05	AC	3 ms; 5,376 KB
testcase_06	AC	2 ms; 5,376 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	2 ms; 5,376 KB
testcase_10	AC	3 ms; 5,376 KB
testcase_11	AC	2 ms; 5,376 KB
testcase_12	AC	2 ms; 5,376 KB
testcase_13	AC	2 ms; 5,376 KB
testcase_14	AC	2 ms; 5,376 KB
testcase_15	AC	61 ms; 5,376 KB
testcase_16	AC	26 ms; 5,376 KB
testcase_17	AC	51 ms; 5,376 KB
testcase_18	AC	32 ms; 5,376 KB
testcase_19	AC	34 ms; 5,376 KB
testcase_20	AC	33 ms; 5,376 KB
testcase_21	AC	66 ms; 5,376 KB
testcase_22	AC	45 ms; 5,376 KB
testcase_23	AC	67 ms; 5,376 KB

ソースコード

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

/**
 * @brief https://tkmst201.github.io/Library/DataStructure/BinaryIndexedTree.hpp
 */
template<typename T>
struct BinaryIndexedTree {
	using value_type = T;
	using const_reference = const value_type &;
	using F = std::function<value_type (const_reference, const_reference)>;
	using size_type = std::size_t;
	
private:
	size_type n;
	F f;
	value_type id_elem;
	std::vector<value_type> node;
	
public:
	BinaryIndexedTree(size_type n, const F & f, const_reference id_elem)
		: n(n), f(f), id_elem(id_elem), node(n + 1, id_elem) {}
	
	size_type size() const noexcept {
		return n;
	}
	
	void add(size_type i, const_reference x) {
		assert(i < size());
		++i;
		for (; i <= size(); i += i & -i) node[i] = f(node[i], x);
	}
	
	value_type sum(size_type i) const {
		assert(i <= size());
		value_type res = id_elem;
		for (; i > 0; i -= i & -i) res = f(node[i], res);
		return res;
	}
	
	size_type lower_bound(const_reference x) const {
		size_type res = 0;
		size_type s = id_elem, w = 1;
		while (w < size()) w <<= 1;
		for (; w > 0; w >>= 1) {
			if (res + w <= size()) {
				value_type cur = f(s, node[res + w]);
				if (cur < x) {
					res += w;
					s = cur;
				}
			}
		}
		return res;
	}
};

int main() {
	int N;
	cin >> N;
	vector<int> A(N), B(N);
	REP(i, N) scanf("%d", &A[i]);
	REP(i, N) scanf("%d", &B[i]);
	sort(ALL(A));
	
	auto compress = [](auto &&v, auto &&cv) -> void {
		for (auto &&u : v) cv.emplace_back(u);
		cv.emplace_back(INF);
		cv.emplace_back(-INF);
		std::sort(std::begin(cv), std::end(cv));
		cv.erase(std::unique(std::begin(cv), std::end(cv)), std::end(cv));
		for (auto &&u : v) u = std::lower_bound(std::begin(cv), std::end(cv), u) - std::begin(cv);
	};
	vector<int> cx;
	compress(B, cx);
	
	BinaryIndexedTree<int> bit(cx.size(), [](int x, int y) { return x + y; }, 0);
	ll ans = 0;
	REP(i, N) {
		bit.add(B[i], 1);
		ans += bit.sum(lower_bound(ALL(cx), A[i]) - cx.begin());
	}
	cout << ans << endl;
}