From 1172d4842b4e062795bfa2acaa13e64224cd31c7 Mon Sep 17 00:00:00 2001
From: Lam Haoyin <root@eatswap.org>
Date: Mon, 4 Apr 2022 18:46:41 +0800
Subject: [PATCH] add: 220404-CN [cpp]

---
 cpp/2204/220404-CN.cpp  | 121 ++++++++++++++++++++++++++++++++++++++++
 cpp/2204/CMakeLists.txt |   2 +-
 2 files changed, 122 insertions(+), 1 deletion(-)
 create mode 100644 cpp/2204/220404-CN.cpp

diff --git a/cpp/2204/220404-CN.cpp b/cpp/2204/220404-CN.cpp
new file mode 100644
index 0000000..cd36cde
--- /dev/null
+++ b/cpp/2204/220404-CN.cpp
@@ -0,0 +1,121 @@
+#include <vector>
+#include <algorithm>
+#include <iostream>
+
+/**
+ * 307. Range Sum Query - Mutable
+ * Given an integer array nums, handle multiple queries of the following types:
+ *
+ * Update the value of an element in nums.
+ * Calculate the sum of the elements of nums between indices left and right inclusive where left <= right.
+ * Implement the NumArray class:
+ *
+ * NumArray(int[] nums) Initializes the object with the integer array nums.
+ * void update(int index, int val) Updates the value of nums[index] to be val.
+ * int sumRange(int left, int right) Returns the sum of the elements of nums between indices left and right inclusive (i.e. nums[left] + nums[left + 1] + ... + nums[right]).
+ */
+
+#ifdef GENERIC
+#include <map>
+#ifdef LOCAL
+template<int maxCacheSize>
+#endif
+class NumArray {
+private:
+#ifndef LOCAL
+	static inline const int maxCacheSize = 192;
+#endif
+	std::vector<int> n;
+
+	std::vector<int> prefixSum;
+
+	std::map<int, int> alterCache;
+public:
+	explicit NumArray(std::vector<int> nums) : n(std::move(nums)) {
+		prefixSum.reserve(n.size());
+		int s = 0;
+		for (int x : n) {
+			s += x;
+			prefixSum.push_back(s);
+		}
+	}
+
+	void update(int index, int val);
+
+	int sumRange(int left, int right) const;
+};
+
+void NumArray::update(int index, int val) {
+	alterCache[index] = val;
+	if (alterCache.size() < maxCacheSize)
+		return;
+	int offset = 0, nSize = n.size();
+	for (auto it = std::next(alterCache.cbegin()); it != alterCache.cend(); ++it) {
+		auto itPrev = std::prev(it);
+		offset += itPrev->second - n[itPrev->first];
+		for (int i = itPrev->first; i < it->first; ++i)
+			prefixSum[i] += offset;
+	}
+	offset += alterCache.crbegin()->second - n[alterCache.crbegin()->first];
+	for (int i = alterCache.crbegin()->first; i < nSize; ++i)
+		prefixSum[i] += offset;
+	for (const auto& [i, v] : alterCache)
+		n[i] = v;
+	alterCache.clear();
+}
+
+int NumArray::sumRange(int left, int right) const {
+	int result = prefixSum[right] - (left > 0 ? prefixSum[left - 1] : 0);
+	for (const auto& [i, v] : alterCache)
+		if (i >= left && i <= right)
+			result += v - n[i];
+	return result;
+}
+#endif // GENERIC
+
+// Segment Tree
+#ifndef GENERIC
+class NumArray {
+private:
+	static inline const int maxSizeBit = 15;
+	static inline const int maxSize = 1 << maxSizeBit;
+
+	int segTree[maxSize << 1];
+
+	int n;
+public:
+	explicit NumArray(const std::vector<int>& nums) {
+		n = nums.size();
+		for (int i = 0; i < n; ++i)
+			segTree[i + maxSize] = nums[i];
+		// Build
+		for (int i = maxSize >> 1; i; i >>= 1)
+			for (int j = i; j < (i << 1); ++j)
+				segTree[j] = segTree[j << 1] + segTree[1 + (j << 1)];
+	}
+
+	void update(int index, int val) {
+		int offset = val - segTree[index + maxSize];
+		for (int i = index + maxSize; i; i >>= 1)
+			segTree[i] += offset;
+	}
+
+	int sumRange(int left, int right) const {
+		std::function<int(int, int, int)> query = [&](int o, int L, int R) {
+			int M = L + ((R - L) >> 1), ret = 0;
+			if (left <= L && R <= right)
+				return segTree[o];
+			if (left <= M)
+				ret += query(o << 1, L, M);
+			if (M < right)
+				ret += query(1 + (o << 1), M + 1, R);
+			return ret;
+		};
+		return query(1, 0, maxSize - 1);
+	}
+};
+#endif // GENERIC
+
+int main() {
+	return 0;
+}
diff --git a/cpp/2204/CMakeLists.txt b/cpp/2204/CMakeLists.txt
index 3b21d97..68c4c84 100644
--- a/cpp/2204/CMakeLists.txt
+++ b/cpp/2204/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2204)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2204 220404.cpp)
+ADD_EXECUTABLE(2204 220404-CN.cpp)