From 05e7b41d06f108a19df58e2d0872fea07b8614ea Mon Sep 17 00:00:00 2001
From: Lam Haoyin <root@eatswap.org>
Date: Mon, 24 Jan 2022 09:40:42 +0800
Subject: [PATCH] add: 220123

---
 2201/220123.cpp     | 44 ++++++++++++++++++++++++++++++++++++++++++++
 2201/CMakeLists.txt |  2 +-
 2 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 2201/220123.cpp

diff --git a/2201/220123.cpp b/2201/220123.cpp
new file mode 100644
index 0000000..bbadfc2
--- /dev/null
+++ b/2201/220123.cpp
@@ -0,0 +1,44 @@
+#include <vector>
+#include <cstdio>
+
+template<int L, int R>
+struct TableGenerator {
+	int answer[50] {};
+	int size = 0;
+
+	constexpr TableGenerator() : answer(), size(0) {
+		auto gen = [](int begin, int digits) {
+			int ret = begin;
+			for (int i = 1; i < digits; ++i) {
+				ret = 10 * ret + (i + begin);
+			}
+			return ret;
+		};
+		int digitsL = 0, beginL, ans = 0;
+		for (int i = L; i; i /= 10) {
+			++digitsL;
+			beginL = i;
+		}
+		for (int d = digitsL, lim = std::min(R, 123456789); ans < lim; ++d) {
+			for (int b = (d == digitsL) ? beginL : 1; ans < lim && b + d <= 10; ++b) {
+				answer[size++] = ans = gen(b, d);
+			}
+		}
+	}
+};
+
+class Solution {
+private:
+	inline static constexpr TableGenerator<10, 1000000000> table;
+public:
+	static std::vector<int> sequentialDigits(int low, int high) {
+		return {std::lower_bound(table.answer, table.answer + table.size, low), std::lower_bound(table.answer, table.answer + table.size, 1 + high)};
+	}
+};
+
+int main() {
+	auto ret = Solution::sequentialDigits(1000, 123456789);
+	for (int i : ret)
+		std::printf("%d\n", i);
+	return 0;
+}
diff --git a/2201/CMakeLists.txt b/2201/CMakeLists.txt
index f6bfbfa..e77ea1a 100644
--- a/2201/CMakeLists.txt
+++ b/2201/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2201)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2201 220123-CN.cpp)
+ADD_EXECUTABLE(2201 220123.cpp)