Added Longest Nice Substring.java

varunu28 · web-flow · commit a768c2ca36ad · 2021-02-20T17:53:43.000-08:00
diff --git a/Easy/Longest Nice Substring.java b/Easy/Longest Nice Substring.java
@@ -0,0 +1,14 @@
+class Solution {
+  public String longestNiceSubstring(String s) {
+    Set<Character> set = s.chars().mapToObj(c -> (char) c).collect(Collectors.toSet());
+    for (int i = 0; i < s.length(); i++) {
+      char c = s.charAt(i);
+      if (!(set.contains(Character.toLowerCase(c)) && set.contains(Character.toUpperCase(c)))) {
+        String left = longestNiceSubstring(s.substring(0, i));
+        String right = longestNiceSubstring(s.substring(i + 1));
+        return left.length() >= right.length() ? left : right; 
+      }
+    }
+    return s;
+  }
+}
