Implement Trie

Hard

0/120

Average time to solve is 41m

225 upvotes

Asked in companies

Problem statement

Implement Trie Data Structure to support these operations:

insert(word) - To insert a string "word" in Trie
search(word) - To check if string "word" is present in Trie or not.
startsWith(word) - To check if there is any string in the Trie that starts with the given prefix string "word".

Three type of queries denote these operations:

Type 1: To insert a string "word" in Trie.
1 word

Type 2: To check if the string "word" is present in Trie or not.
2 word

Type 3: To check if there is any string in the Trie that starts with the given prefix string "word".
3 word

Detailed explanation ( Input/output format, Notes, Images )

Input format :

The first line contains an Integer 'Q' which denotes the number of queries to be run. Then next 'Q' lines denote each query:

The first and only line of each query contains the type of query and a string "word" separated by a single space.

Output format :

For each query of Type 2 print the string "true" if string "word" is present in Trie or "false" otherwise.
For each query of Type 3 print the string "true" if there is any string in the Trie that starts with the given prefix string "word" or "false" otherwise.

Output for every query will be printed in a separate line.

Note:

You are not required to print the output explicitly, it has already been taken care of. Just implement the function.

Constraints :

1 <= Q <= 5*10^4
1 <= W <= 10

Where 'Q' is the number of queries, and 'W' is the length of the "word".
All input of "word" will consist of only lowercase letters a-z.

Sample Input 1 :

5
1 hello
1 help
2 help
3 hel
2 hel

Sample Output 1 :

true
true
false

Explanation to Sample Input 1 :

Query 1: "hello" is inserted
Query 2: "help" is inserted
Query 3: "true" is printed as "help" is present
Query 4: "true" is printed as "hello" and "help" is present having the prefix "hel"
Query 5: "false" is printed as "hel" is not present

Sample Input 2 :

10
1 aaaa
1 aaaaaa
1 bcd
2 aaaaa
3 aaaaa
3 bc
2 bc
1 bc
3 bcda
2 bc

Sample Output 2 :

false
true
true
false
false
true

Explanation to Sample Input 2 :

Query 1: "aaaa" is inserted
Query 2: "aaaaaa" is inserted
Query 3: "bcd" is inserted
Query 4: "false" is printed as "aaaaa" is not present
Query 5: "true" is printed as "aaaaaa" is present having the prefix "aaaaa"
Query 6: "true" is printed as "bcd" is present having the prefix "bc"
Query 7: "false" is printed as "bc" is not present
Query 8: "bc" is inserted
Query 9: "false" is printed as no word is present having the prefix "bcda"
Query 10: "true" is printed as "bc" is present

Console