add: 220316 [cpp]

cpp/2203/220316.cpp

@@ -0,0 +1,40 @@
+#include <stack>
+#include <vector>
+#include <unordered_map>
+#include <iostream>
+
+class Solution {
+public:
+	static bool validateStackSequences(const std::vector<int>& pushed, const std::vector<int>& popped) {
+		const int n = pushed.size();
+
+		std::unordered_map<int, int> m;
+		for (int i = 0; i < n; ++i)
+			m[pushed[i]] = i;
+
+		std::vector<int> processed(n);
+		for (int i = 0; i < n; ++i)
+			processed[i] = m[popped[i]];
+
+		int currentPushed = -1;
+		std::stack<int> s;
+		for (int i = 0; i < n; ++i) {
+			if (processed[i] > currentPushed) {
+				// == Push to current, and pop current immediately
+				for (++currentPushed; currentPushed < processed[i]; ++currentPushed) {
+					s.push(currentPushed);
+				}
+			} else {
+				if (s.empty() || s.top() != processed[i])
+					return false;
+				s.pop();
+			}
+		}
+		return true;
+	}
+};
+
+int main() {
+	std::cout << Solution::validateStackSequences({1,2,3,4,5}, {1,2,3,4,5});
+	return 0;
+}

cpp/2203/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2203)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2203 220315.cpp)
+ADD_EXECUTABLE(2203 220316.cpp)