leetcode update

Author: zhongn2

Anagrams.cpp

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+//Anagrams
+//Given an array of strings, return all groups of strings that are anagrams.
+//Note: All inputs will be in lower-case.
+

Length of Last Word.cpp

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+//Length of Last Word
+
+//method 1: NO STL
+class Solution {
+public:
+    int lengthOfLastWord(const char *s) {
+        int length = strlen(s);
+        if(length == 0) return 0;
+        int lengthofLast = 0;
+		// visit from back, add 1 to length when it does not meet with " " 
+		// stop at " "
+        for(int i = length - 1; i >= 0; i--){
+            if(s[i] != ' ') lengthofLast ++;
+            else { // e.g "a ".  we have to check the length is greater than 0
+                if(lengthofLast > 0) return lengthofLast;
+            }
+        }
+        return lengthofLast;
+        
+    }
+};
+
+// method 2: STL
+// find the first alpha and start from the alpha, find isnot alpha one.
+class Solution {
+public:
+    int lengthOfLastWord(const char *s) {
+      const string str(s);
+      auto first = find_if(str.rbegin(), str.rend(), ::isalpha);
+      auto last = find_if_not(first, str.rend(), ::isalpha);
+      return distance(first, last);
+    }
+};