From cec4f35834f64aa7b47d3f9461cc7c394c43bca6 Mon Sep 17 00:00:00 2001
From: Eatswap <root@eatswap.org>
Date: Fri, 31 Mar 2023 18:38:41 +0800
Subject: [PATCH] add: 230330

---
 cpp/2303/230330.cpp     | 54 +++++++++++++++++++++++++++++++++++++++++
 cpp/2303/CMakeLists.txt |  2 +-
 2 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 cpp/2303/230330.cpp

diff --git a/cpp/2303/230330.cpp b/cpp/2303/230330.cpp
new file mode 100644
index 0000000..6347bdb
--- /dev/null
+++ b/cpp/2303/230330.cpp
@@ -0,0 +1,54 @@
+#include <string>
+
+/**
+ * 87. Scramble String
+ * We can scramble a string s to get a string t using the following algorithm:
+ *
+ * If the length of the string is 1, stop.
+ * If the length of the string is > 1, do the following:
+ * Split the string into two non-empty substrings at a random index, i.e., if the string is s, divide it to x and y where s = x + y.
+ * Randomly decide to swap the two substrings or to keep them in the same order. i.e., after this step, s may become s = x + y or s = y + x.
+ * Apply step 1 recursively on each of the two substrings x and y.
+ * Given two strings s1 and s2 of the same length, return true if s2 is a scrambled string of s1, otherwise, return false.
+ */
+
+class Solution {
+private:
+	// Const Char Pointer
+	using CCP = const char*;
+
+	CCP s = nullptr, t = nullptr;
+	int dp[31][31][31][31]{};
+
+	bool f(int m, int n, int p, int q) {
+		if (m + 1 == n)
+			return s[m] == t[p];
+		int& ans = dp[m][n][p][q];
+		if (ans)
+			return (ans + 1);
+		ans = 1;
+		for (int i = m, j = p; i < n; ++i, ++j) {
+			if (s[i] != t[j]) {
+				ans = 0;
+				break;
+			}
+		}
+		if (ans)
+			return ans;
+		for (int i = m + 1; i < n; ++i) {
+			if (f(m, i, p, p - m + i) && f(i, n, p - m + i, q))
+				return ans = 1;
+			if (f(m, i, q - (i - m), q) && f(i, n, p, q - (i - m)))
+				return ans = 1;
+		}
+		ans = -1;
+		return false;
+	}
+
+public:
+	bool isScramble(const std::string& s1, const std::string& s2) {
+		s = s1.c_str();
+		t = s2.c_str();
+		return f(0, s1.length(), 0, s2.length());
+	}
+};
diff --git a/cpp/2303/CMakeLists.txt b/cpp/2303/CMakeLists.txt
index 640f7d2..3a27cdf 100644
--- a/cpp/2303/CMakeLists.txt
+++ b/cpp/2303/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2303)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2303 230331-CN.cpp)
+ADD_EXECUTABLE(2303 230330.cpp)