New Problem Solution "Detect Capital"

Author: haoel

README.md

@@ -56,6 +56,7 @@ LeetCode
 |543|[Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/) | [Python](./algorithms/python/DiameterOfBinaryTree/diameterOfBinaryTree.py)|Easy|
 |538|[Convert BST to Greater Tree](https://leetcode.com/problems/convert-bst-to-greater-tree/) | [Python](./algorithms/python/ConvertBSTtoGreaterTree/convertBST.py)|Easy|
 |532|[K-diff Pairs in an Array](https://leetcode.com/problems/k-diff-pairs-in-an-array/) | [Python](./algorithms/python/K-diffPairsInAnArray/findPairs.py)|Easy|
+|520|[Detect Capital](https://leetcode.com/problems/detect-capital/) | [C++](./algorithms/cpp/detectCapital/DetectCapital.cpp)|Easy|
 |509|[Fibonacci Number](https://leetcode.com/problems/fibonacci-number/) | [Python](./algorithms/python/FibonacciNumber/fib.py)|Easy|
 |477|[Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/) | [C++](./algorithms/cpp/totalHammingDistance/totalHammingDistance.cpp)|Medium|
 |450|[DeleteNodeInABST](https://leetcode.com/problems/delete-node-in-a-bst/) | [Python](./algorithms/python/DeleteNodeInABST/deleteNode.py)|Medium|

algorithms/cpp/detectCapital/DetectCapital.cpp

@@ -0,0 +1,50 @@
+// Source : https://leetcode.com/problems/detect-capital/
+// Author : Hao Chen
+// Date   : 2019-02-04
+
+/***************************************************************************************************** 
+ *
+ * 
+ * Given a word, you need to judge whether the usage of capitals in it is right or not.
+ * 
+ * We define the usage of capitals in a word to be right when one of the following cases holds:
+ * 
+ * All letters in this word are capitals, like "USA".
+ * All letters in this word are not capitals, like "leetcode".
+ * Only the first letter in this word is capital if it has more than one letter, like "Google".
+ * 
+ * Otherwise, we define that this word doesn't use capitals in a right way.
+ * 
+ * Example 1:
+ * 
+ * Input: "USA"
+ * Output: True
+ * 
+ * Example 2:
+ * 
+ * Input: "FlaG"
+ * Output: False
+ * 
+ * Note:
+ * The input will be a non-empty word consisting of uppercase and lowercase latin letters.
+ ******************************************************************************************************/
+class Solution {
+    bool is_lower(char ch) {
+        return ch >='a' && ch <='z';
+    }
+    bool is_upper(char ch) {
+        return ch >='A' && ch <='Z';
+    }
+    bool is_alpha(char ch) {
+        return is_lower(ch) || is_upper(ch);
+    }
+public:
+    bool detectCapitalUse(string word) {
+        bool all_upper = true, all_lower = true, first = is_upper(word[0]);
+        for(int i=1; i<word.size(); i++) {
+            if (is_lower(word[i])) all_upper = false;
+            if (is_upper(word[i])) all_lower = false;
+        }
+        return all_lower || first && all_upper; 
+    }
+};