add: 220508 [cpp]

cpp/2205/220508.cpp

@@ -0,0 +1,115 @@
+#include <vector>
+#include <functional>
+
+// This is the interface that allows for creating nested lists.
+// You should not implement it, or speculate about its implementation
+class NestedInteger {
+private:
+	std::vector<NestedInteger> content;
+
+	int x = 0x7FFFFFFF;
+
+public:
+	// Constructor initializes an empty nested list.
+	explicit NestedInteger();
+
+	// Constructor initializes a single integer.
+	explicit NestedInteger(int value);
+
+	// Return true if this NestedInteger holds a single integer, rather than a nested list.
+	bool isInteger() const;
+
+	// Return the single integer that this NestedInteger holds, if it holds a single integer
+	// The result is undefined if this NestedInteger holds a nested list
+	int getInteger() const;
+
+	// Set this NestedInteger to hold a single integer.
+	void setInteger(int value);
+
+	// Set this NestedInteger to hold a nested list and adds a nested integer to it.
+	void add(const NestedInteger& ni);
+
+	// Return the nested list that this NestedInteger holds, if it holds a nested list
+	// The result is undefined if this NestedInteger holds a single integer
+	[[nodiscard]] const std::vector<NestedInteger>& getList() const;
+};
+
+/**
+ * 341. Flatten Nested List Iterator
+ * You are given a nested list of integers nestedList. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an iterator to flatten it.
+ *
+ * Implement the NestedIterator class:
+ *
+ * NestedIterator(List<NestedInteger> nestedList) Initializes the iterator with the nested list nestedList.
+ * int next() Returns the next integer in the nested list.
+ * boolean hasNext() Returns true if there are still some integers in the nested list and false otherwise.
+ */
+
+class NestedIterator {
+private:
+	int v[512];
+	int ptr = 0, rear = 0;
+
+	void dfs(const NestedInteger& n) {
+		if (n.isInteger())
+			v[rear++] = n.getInteger();
+		else {
+			const auto& list = n.getList();
+			const int s = list.size();
+			for (int i = 0; i < s; ++i)
+				dfs(list[i]);
+		}
+	}
+
+public:
+	explicit NestedIterator(const std::vector<NestedInteger>& list) {
+		const int s = list.size();
+		for (int i = 0; i < s; ++i)
+			dfs(list[i]);
+	}
+
+	int next() {
+		return v[ptr++];
+	}
+
+	bool hasNext() {
+		return ptr < rear;
+	}
+};
+
+
+int main() {
+	return 0;
+}
+
+NestedInteger::NestedInteger() = default;
+
+NestedInteger::NestedInteger(int value) : x(value) {}
+
+bool NestedInteger::isInteger() const {
+	return x < 0x7FFFFFFE;
+}
+
+int NestedInteger::getInteger() const {
+	return x;
+}
+
+void NestedInteger::setInteger(int value) {
+	x = value;
+	content.clear();
+}
+
+void NestedInteger::add(const NestedInteger& ni) {
+	if (!this->isInteger()) {
+		content.push_back(ni);
+		return;
+	}
+	content.clear();
+	content.emplace_back(x);
+	content.push_back(ni);
+	x = 0x7FFFFFFF;
+}
+
+const std::vector<NestedInteger>& NestedInteger::getList() const {
+	return content;
+}

cpp/2205/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2205)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2205 220507.cpp)
+ADD_EXECUTABLE(2205 220508.cpp)