@@ -0,0 +1,27 @@
+package com.hellokoding.algorithm;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class String_LongestDistinct {
+    static String lengthOfLongestSubstring(String s) {
+        int n = s.length();
+        int l = 0, i = 0, j = 0;
+        Set<Character> chars = new HashSet<>();
+
+        while(i < n && j < n) {
+            if(!chars.contains(s.charAt(j))) {
+                chars.add(s.charAt(j++));
+                l = Math.max(l, j-i);
+            } else {
+                chars.remove(s.charAt(i++));
+            }
+        }
+
+        return s.substring(i, i+l);
+    }
+
+    public static void main(String[] args) {
+        System.out.println(lengthOfLongestSubstring("Hello Koding"));
+    }
+}
@@ -3,7 +3,7 @@
 public class String_LongestPalindrome_DP {
     static String findLongestPalindromicSubstring(String S) {
         int n = S.length();
-        int start = 0;
+        int startIndex = 0;
         int maxLength = 1;
         boolean[][] P = new boolean[n][n];
 
@@ -14,7 +14,7 @@ static String findLongestPalindromicSubstring(String S) {
         for (int i = 0; i < n - 1; i++) {
             if (S.charAt(i) == S.charAt(i+1)) {
                 P[i][i+1] = true;
-                start = i;
+                startIndex = i;
                 maxLength = 2;
             }
         }
@@ -27,13 +27,13 @@ static String findLongestPalindromicSubstring(String S) {
 
                     if (l > maxLength) {
                         maxLength = l;
-                        start = i;
+                        startIndex = i;
                     }
                 }
             }
         }
 
-        return S.substring(start, start + maxLength);
+        return S.substring(startIndex, startIndex + maxLength);
     }
 
     public static void main(String[] args) {
Original file line number	Diff line number	Diff line change
`@@ -3,7 +3,7 @@`
`3`	`3`	`public class String_LongestPalindrome_DP {`
`4`	`4`	`static String findLongestPalindromicSubstring(String S) {`
`5`	`5`	`int n = S.length();`
`6`		`- int start = 0;`
	`6`	`+ int startIndex = 0;`
`7`	`7`	`int maxLength = 1;`
`8`	`8`	`boolean[][] P = new boolean[n][n];`
`9`	`9`
`@@ -14,7 +14,7 @@ static String findLongestPalindromicSubstring(String S) {`
`14`	`14`	`for (int i = 0; i < n - 1; i++) {`
`15`	`15`	`if (S.charAt(i) == S.charAt(i+1)) {`
`16`	`16`	`P[i][i+1] = true;`
`17`		`- start = i;`
	`17`	`+ startIndex = i;`
`18`	`18`	`maxLength = 2;`
`19`	`19`	`}`
`20`	`20`	`}`
`@@ -27,13 +27,13 @@ static String findLongestPalindromicSubstring(String S) {`
`27`	`27`
`28`	`28`	`if (l > maxLength) {`
`29`	`29`	`maxLength = l;`
`30`		`- start = i;`
	`30`	`+ startIndex = i;`
`31`	`31`	`}`
`32`	`32`	`}`
`33`	`33`	`}`
`34`	`34`	`}`
`35`	`35`
`36`		`- return S.substring(start, start + maxLength);`
	`36`	`+ return S.substring(startIndex, startIndex + maxLength);`
`37`	`37`	`}`
`38`	`38`
`39`	`39`	`public static void main(String[] args) {`