add: 220221-CN [cpp]

cpp/2202/220221-CN.cpp

@@ -0,0 +1,49 @@
+#include <string>
+#include <queue>
+
+class Solution {
+public:
+	std::string pushDominoes(const std::string& dominoes) {
+		std::queue<int> q;
+		int n = dominoes.length();
+
+		int result[100005]{}, lastModified[100005]{};
+
+		for (int i = 0; i < n; ++i) {
+			if ('.' != dominoes[i]) {
+				q.push(i);
+				q.push(1);
+				lastModified[i] = 1;
+				result[i] = ((dominoes[i] == 'L') ? -1 : 1);
+			}
+		}
+
+		while (!q.empty()) {
+			int pos = q.front();
+			q.pop();
+			int tP = q.front();
+			q.pop();
+
+			if (pos && (lastModified[pos - 1] == tP + 1 || !lastModified[pos - 1]) && result[pos] < 0) {
+				if (!lastModified[pos - 1]) {
+					q.push(pos - 1);
+					q.push(lastModified[pos - 1] = tP + 1);
+				}
+				--result[pos - 1];
+			} else if (pos < n - 1 && (lastModified[pos + 1] == tP + 1 || !lastModified[pos + 1]) && result[pos] > 0) {
+				if (!lastModified[pos + 1]) {
+					q.push(pos + 1);
+					q.push(lastModified[pos + 1] = tP + 1);
+				}
+				++result[pos + 1];
+			}
+		}
+
+		std::string ret;
+		ret.reserve(n);
+		for (int i = 0; i < n; ++i) {
+			ret.push_back(result[i] ? (result[i] > 0 ? 'R' : 'L') : '.');
+		}
+		return ret;
+	}
+};

cpp/2202/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2202)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2202 220220.cpp)
+ADD_EXECUTABLE(2202 220221-CN.cpp)