Added corner case while querying a string in trie

Author: mohit

src/main/java/main/java/videos/Tries.java

@@ -14,6 +14,7 @@ public static void main(String[] args) {
  final Trie trie = new Trie();
  setOfStrings.forEach(trie::insert);
  System.out.println(trie.query("psst"));
+ System.out.println(trie.query("psstq"));
  trie.update("qqrs", "psst");
  System.out.println(trie.query("qqrs"));
  System.out.println(trie.query("psst"));
@@ -30,10 +31,11 @@ public Trie() {
  public int query(final String s) {
  TrieNode current = root;
  for (int i = 0; i < s.length(); i++) {
- if (current == null) {
- return 0;
- }
- current = current.next(s.charAt(i));
+ if(current==null || current.next(s.charAt(i))==null) {
+return 0;
+}
+else
+current=current.next(s.charAt(i));
  }
  return current.terminating;
  }