From fe2a0b670763439b4caaaf08c7ca6d07313d1cb1 Mon Sep 17 00:00:00 2001
From: Eatswap <root@eatswap.org>
Date: Tue, 4 Apr 2023 23:30:23 +0800
Subject: [PATCH] add: 230404-CN

---
 cpp/2304/230404-CN.cpp  | 37 +++++++++++++++++++++++++++++++++++++
 cpp/2304/CMakeLists.txt |  2 +-
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 cpp/2304/230404-CN.cpp

diff --git a/cpp/2304/230404-CN.cpp b/cpp/2304/230404-CN.cpp
new file mode 100644
index 0000000..6da2dd2
--- /dev/null
+++ b/cpp/2304/230404-CN.cpp
@@ -0,0 +1,37 @@
+#include <vector>
+
+/**
+ * 1000. Minimum Cost to Merge Stones
+ *
+ * There are n piles of stones arranged in a row. The ith pile has stones[i] stones.
+ * A move consists of merging exactly k consecutive piles into one pile, and the cost of this move is equal to the total number of stones in these k piles.
+ * Return the minimum cost to merge all piles of stones into one pile. If it is impossible, return -1.
+ */
+
+class Solution {
+public:
+	static int mergeStones(const std::vector<int>& stones, int k) {
+		const int n = stones.size();
+		if (n == 1)
+			return 0;
+		if (n < k || k != 2 && (n % (k - 1)) != 1)
+			return -1;
+		int pSum[35]{ stones[0] };
+		for (int i = 1; i < n; ++i)
+			pSum[i] = pSum[i - 1] + stones[i];
+		int dp[35][35]{};
+		std::memset(dp, 0x3F, sizeof dp);
+		for (int i = 0; i < n; ++i)
+			dp[i][i] = 0;
+		for (int len = 2; len <= n; ++len) {
+			for (int L = 0; L < n && L + len <= n; ++L) {
+				int R = L + len - 1; // inclusive
+				for (int M = L; M < R; M += k - 1)
+					dp[L][R] = std::min(dp[L][M] + dp[M + 1][R], dp[L][R]);
+				if (0 == (R - L) % (k - 1))
+					dp[L][R] += pSum[R] - (L ? pSum[L - 1] : 0);
+			}
+		}
+		return dp[0][n - 1];
+	}
+};
diff --git a/cpp/2304/CMakeLists.txt b/cpp/2304/CMakeLists.txt
index 5c8082e..56933e0 100644
--- a/cpp/2304/CMakeLists.txt
+++ b/cpp/2304/CMakeLists.txt
@@ -4,4 +4,4 @@ PROJECT(2304)
 SET(CMAKE_CXX_STANDARD 23)
 SET(CMAKE_EXPORT_COMPILE_COMMANDS true)
 
-ADD_EXECUTABLE(2304 230403.cpp)
+ADD_EXECUTABLE(2304 230404-CN.cpp)