1118 added.

liuyubobobo · liuyubobobo · commit d1643a37e6ea · 2019-07-13T19:06:20.000-07:00
diff --git a/1118-Number-of-Days-in-a-Month/cpp-1118/CMakeLists.txt b/1118-Number-of-Days-in-a-Month/cpp-1118/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.14)
+project(A)
+
+set(CMAKE_CXX_STANDARD 14)
+
+add_executable(A main.cpp)
diff --git a/1118-Number-of-Days-in-a-Month/cpp-1118/main.cpp b/1118-Number-of-Days-in-a-Month/cpp-1118/main.cpp
@@ -0,0 +1,34 @@
+/// Source : https://leetcode.com/problems/number-of-days-in-a-month/
+/// Author : liuyubobobo
+/// Time   : 2019-07-13
+
+#include <iostream>
+#include <unordered_set>
+
+using namespace std;
+
+
+/// Simulation
+/// Time Complexity: O(1)
+/// Space Complexity: O(1)
+class Solution {
+public:
+    int numberOfDays(int Y, int M) {
+
+        unordered_set<int> thirtyone = {1, 3, 5, 7, 8, 10, 12};
+        if(thirtyone.count(M)) return 31;
+        if(M == 2) return isLeapYear(Y) ? 29 : 28;
+        return 30;
+    }
+
+private:
+    bool isLeapYear(int Y){
+        return (!(Y % 4) && (Y % 100)) || !(Y % 400);
+    }
+};
+
+
+int main() {
+
+    return 0;
+}
diff --git a/readme.md b/readme.md
@@ -761,4 +761,6 @@ email: [liuyubobobo@gmail.com](mailto:liuyubobobo@gmail.com)
 | 1109 | [Corporate Flight Bookings](https://leetcode.com/problems/corporate-flight-bookings/) | [无] | [C++](1109-Corporate-Flight-Bookings/cpp-1009/) | | |
 | 1110 | [Delete Nodes And Return Forest](https://leetcode.com/problems/delete-nodes-and-return-forest/) | [无] | [C++](1110-Delete-Nodes-And-Return-Forest/cpp-1110/) | | |
 | 1111 | [Maximum Nesting Depth of Two Valid Parentheses Strings](https://leetcode.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings/) | [无] | [C++](1111-Maximum-Nesting-Depth-of-Two-Valid-Parentheses-Strings/cpp-1111/) | | |
-| | | | | | |
+| | | | | | |
+| 1118 | [Number of Days in a Month](https://leetcode.com/problems/number-of-days-in-a-month/) | [无] | [C++](1118-Number-of-Days-in-a-Month/cpp-1118/) | | |
+| | | | | | |
