From 4c29b90e4221ab1381758b92dc4628dae8a27a68 Mon Sep 17 00:00:00 2001
From: nidhibudhraja <nidhi.budhraja96@gmail.com>
Date: Fri, 18 Oct 2019 18:22:17 +0530
Subject: [PATCH] longestPalin.cpp

Longest palindrome algorithm
---
 DP/longestPalin.cpp | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 DP/longestPalin.cpp

diff --git a/DP/longestPalin.cpp b/DP/longestPalin.cpp
new file mode 100644
index 00000000..bfae9639
--- /dev/null
+++ b/DP/longestPalin.cpp
@@ -0,0 +1,20 @@
+class Solution {
+public:
+    string expand(const string &s, int left, int right){
+        const size_t n = s.length();
+        while(left >= 0 && right < n && s[left] == s[right]) left--, right++;
+        return s.substr(left + 1, right - left - 1);
+    }
+    string longestPalindrome(string s) {
+        const size_t n = s.length();
+        if(n == 0) return "";
+        string res = s.substr(0, 1), temp;
+        for(int i = 0; i < n - 1; ++i){
+            temp = expand(s, i, i);
+            if(temp.length() > res.length()) res = temp;
+            temp = expand(s, i, i + 1);
+            if(temp.length() > res.length()) res = temp;
+        }
+        return res;
+    }
+};