valid-palindrom solution

Author: dylan-jung

valid-palindrome/dylan-jung.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+    bool isPalindrome(string s) {
+        string p;
+        for(char const& c: s) {
+            if('A' <= c && c <= 'Z') {
+                p.push_back(c - 'A' + 'a');
+            }
+            else if('a' <= c && c <= 'z') {
+                p.push_back(c);
+            }
+            else if ('0' <= c && c <= '9') {
+                p.push_back(c);
+            }
+        }
+        int start = 0, end = p.size()-1;
+        while(start <= end) {
+            if(p[start++] != p[end--]) return false;
+        }
+        return true;
+    }
+};