#703 solved

Author: shivanand-patil

Arrays/add_valid_palindrome.java

@@ -0,0 +1,27 @@
+/*
+Write a function that takes a string as input and checks whether it can be a valid palindrome by removing at most one character from it.
+Example 1:
+
+Input: s = "aba"
+Output: true
+*/
+
+class Solution {
+    public boolean validPalindrome(String s) {
+        int i=0,j=s.length()-1;     // initialize two pointers, i and j to the start and end of the string respectively
+        while(i<j){                 // loop until i is less than j
+            if(s.charAt(i)!=s.charAt(j))   // if the characters at i and j are not equal
+                return isPalindrome(s,i+1,j) || isPalindrome(s,i,j-1);   // check if the string is a palindrome by removing either the character at i or j and return true if it is a palindrome
+            j--;i++;                // update the pointers
+        }
+        return true;                // if the loop completes without returning false, the string is a palindrome
+    }
+    public static boolean isPalindrome(String ss,int i, int j){     // a helper function to check if a given substring is a palindrome
+        while(i<j){
+            if(ss.charAt(i)!= ss.charAt(j)) return false;  // if the characters at i and j are not equal, the substring is not a palindrome
+            i++;j--;                // update the pointers
+        }
+        return true;                // if the loop completes without returning false, the substring is a palindrome
+    }
+}
+