add: 220419-CN [cpp]

cpp/2204/220419-CN.cpp

@@ -0,0 +1,30 @@
+#include <algorithm>
+#include <string>
+#include <vector>
+
+/**
+ * 821. Shortest Distance to a Character
+ * Given a string s and a character c that occurs in s, return an array of integers answer where answer.length == s.length and answer[i] is the distance from index i to the closest occurrence of character c in s.
+ * The distance between two indices i and j is abs(i - j), where abs is the absolute value function.
+ */
+
+class Solution {
+public:
+	static std::vector<int> shortestToChar(const std::string& s, char c) {
+		int n = s.length();
+		std::vector<int> ret(n, 0x7FFFFFFF);
+		for (int prev = -1, i = 0; i < n; ++i) {
+			if (s[i] == c)
+				prev = i;
+			if (prev != -1)
+				ret[i] = std::min(ret[i], std::abs(prev - i));
+		}
+		for (int prev = -1, i = n - 1; i >= 0; --i) {
+			if (s[i] == c)
+				prev = i;
+			if (prev != -1)
+				ret[i] = std::min(ret[i], std::abs(prev - i));
+		}
+		return ret;
+	}
+};

cpp/2204/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2204)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2204 220418.cpp)
+ADD_EXECUTABLE(2204 220419-CN.cpp)