added solution 5 with it's test case

rushi7997 · rushi7997 · commit ba7fd2eecd81 · 2022-02-23T00:41:36.000-05:00
diff --git a/src/solutions/5/index.ts b/src/solutions/5/index.ts
@@ -0,0 +1,12 @@
+import LongestPalindromicSubstring from './longestPalindrome';
+
+const run = () => {
+    const input = 'babad';
+    console.log("Input: ", input);
+
+    console.time('longestPalindrome');
+    console.log("Output: ", LongestPalindromicSubstring(input));
+    console.timeEnd('longestPalindrome');
+}
+
+export default run;
diff --git a/src/solutions/5/longestPalindrome.test.ts b/src/solutions/5/longestPalindrome.test.ts
@@ -0,0 +1,8 @@
+import longestPalindrome from "./longestPalindrome";
+
+test('Solution 5 - Longest Palindrome', () => {
+    expect(longestPalindrome('babad')).toBe('bab');
+    expect(longestPalindrome('cbbd')).toBe('bb');
+    expect(longestPalindrome('a')).toBe('a');
+    expect(longestPalindrome('abcdefgfedcba')).toBe('abcdefgfedcba');
+})
diff --git a/src/solutions/5/longestPalindrome.ts b/src/solutions/5/longestPalindrome.ts
@@ -0,0 +1,28 @@
+const longestPalindrome = (s: string): string => {
+    let max = 0;
+    let res = '';
+    for (let i = 0; i < s.length; i++) {
+        for (let j = i + 1; j <= s.length; j++) {
+            if (s.slice(i, j).length > max && isPalindrome(s.slice(i, j))) {
+                max = s.slice(i, j).length;
+                res = s.slice(i, j);
+            }
+        }
+    }
+    return res;
+};
+
+const isPalindrome = (s: string): boolean => {
+    let i = 0;
+    let j = s.length - 1;
+    while (i < j) {
+        if (s[i] !== s[j]) {
+            return false;
+        }
+        i++;
+        j--;
+    }
+    return true;
+};
+
+export default longestPalindrome;
