0008: Length of Longest Substring

ashcoding · ashcoding · commit 247b15bcc4c8 · 2017-07-27T18:20:04.000+08:00
diff --git a/0008/Solution.java b/0008/Solution.java
@@ -0,0 +1,34 @@
+import java.util.HashSet;
+
+public class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        int n = s.length();
+        int longest = 0;
+        int i = 0, j = 0;
+        HashSet<Character> set = new HashSet<>();
+        while (i < n && j < n) {
+
+            if (!set.contains(s.charAt(j))) {
+                set.add(s.charAt(j));
+                j++;
+                longest = Math.max(longest, j - i);
+            } else {
+                set.remove(s.charAt(i));
+                i++;
+            }
+        }
+        return longest;
+    }
+
+    public static void main(String[] args) {
+        Solution sol = new Solution();
+
+        System.out.println("Expected 3 - Ans " + sol.lengthOfLongestSubstring("dvdf"));
+        System.out.println("Expected 1 - Ans " + sol.lengthOfLongestSubstring("c"));
+        System.out.println("Expected 3 - Ans " + sol.lengthOfLongestSubstring("abcabcbb"));
+        System.out.println("Expected 1 - Ans " + sol.lengthOfLongestSubstring("bbbbb"));
+        System.out.println("Expected 3 - Ans " + sol.lengthOfLongestSubstring("pwwkew"));
+        // https://leetcode.com/problems/longest-substring-without-repeating-characters/tabs/description
+
+    }
+}
