Create valid-palindrome-ii.cpp

xiwhuang · Sep 17, 2017 · 4730949 · 4730949
1 parent 6831c21
commit 4730949
Showing 1 changed file with 27 additions and 0 deletions.
diff --git a/C++/valid-palindrome-ii.cpp b/C++/valid-palindrome-ii.cpp
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+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    bool validPalindrome(string s) {
+        int left = 0, right = s.length() - 1;
+        while (left < right) {
+            if (s[left] != s[right]) {
+                return validPalindrome(s, left, right - 1) || validPalindrome(s, left + 1, right);
+            }
+            ++left, --right;
+        }
+        return true;
+    }
+
+private:
+    bool validPalindrome(const string& s, int left, int right) {
+        while (left < right) {
+            if (s[left] != s[right]) {
+                return false;
+            }
+            ++left, --right;
+        }
+        return true;
+    }
+};