35.Longest Palindromic Substring

Author: Ibraam-Nashaat

35.Longest Palindromic Substring.cpp

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+
+// Problem Description: https://leetcode.com/problems/longest-palindromic-substring/
+
+class Solution {
+public:
+    string longestPalindrome(string s) {
+        int l, r, resl, resr, reslen = 0;
+        string res;
+        for (int i = 0; i < s.size(); i++)
+        {
+            l = r = i;
+            helper(s, l, r, resl, resr, reslen);
+            l = i;
+            r = i + 1;
+            helper(s, l, r, resl, resr, reslen);
+
+        }
+        return s.substr(resl, resr - resl + 1);
+
+    }
+    void helper(string& s, int& l, int& r, int& resl, int& resr, int& reslen)
+    {
+        while (l >= 0 && r < s.size() && s[l] == s[r])
+        {
+            if (r - l + 1 > reslen)
+            {
+                resl = l;
+                resr = r;
+                reslen = r - l + 1;
+            }
+            l -= 1;
+            r += 1;
+        }
+    }
+};