From 5e1e7d81a43e7aef09c1631d554554d06bdc6c31 Mon Sep 17 00:00:00 2001
From: Lam Haoyin <root@eatswap.org>
Date: Wed, 2 Feb 2022 11:40:40 +0800
Subject: [PATCH] add: 220202

---
 2202/220202.cpp     | 39 +++++++++++++++++++++++++++++++++++++++
 2202/CMakeLists.txt |  2 +-
 2 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 2202/220202.cpp

diff --git a/2202/220202.cpp b/2202/220202.cpp
new file mode 100644
index 0000000..f00539e
--- /dev/null
+++ b/2202/220202.cpp
@@ -0,0 +1,39 @@
+#include <vector>
+#include <string>
+
+class Solution {
+private:
+	template<int N>
+	static inline constexpr int alter(int n) {
+		return n ? -(n == N) : 1;
+	}
+public:
+	static std::vector<int> findAnagrams(const std::string& s, const std::string& p) {
+		std::vector<int> ret;
+		int np = p.length(), ns = s.length();
+
+		int cnt[26]{};
+		for (char ch : p)
+			--cnt[ch - 'a'];
+		for (int i = std::min(np, ns); i--;)
+			++cnt[s[i] - 'a'];
+
+		// Interval: [L, R)
+		int C = std::count(cnt, cnt + 26, 0);
+		for (int L = 0, R = np; R < ns; ++L, ++R) {
+			if (26 == C)
+				ret.push_back(L);
+			C += alter<-1>(--cnt[s[L] - 'a']) + alter<1>(++cnt[s[R] - 'a']);
+		}
+		if (26 == std::count(cnt, cnt + 26, 0))
+			ret.push_back(ns - np);
+		return ret;
+	}
+};
+
+int main() {
+	auto ret = Solution::findAnagrams("cbaebabacd", "abc");
+	for (int i : ret)
+		std::printf("%d ", i);
+	return 0;
+}
diff --git a/2202/CMakeLists.txt b/2202/CMakeLists.txt
index cb0e1e3..5b90e21 100644
--- a/2202/CMakeLists.txt
+++ b/2202/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2202)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2202 220202-CN.cpp)
+ADD_EXECUTABLE(2202 220202.cpp)