Problem: Two Sum III - Data structure design

Easy

15 min

Understand how to design and implement a custom TwoSum data structure that efficiently handles a stream of numbers and checks if any pair sums to a specific value. This lesson guides you through constructing methods to add numbers and find target sums, helping you develop practical skills for coding interviews.

Statement

Design a data structure that takes in a stream of numbers and can check if any two numbers add up to a specific value.

Implement the TwoSum class with the following constructor and methods:

Constructor: Sets up the TwoSum object with an empty list at the start.
void add(int number): Adds a new number to the list.
boolean find(int value): Returns TRUE if any two numbers in the list add up to the given value. If not, it returns FALSE.

Constraints:

$-10^5 \leq$ number $\leq 10^5$
$-2^{31} \leq$ value $\leq 2^{31} -1$
At most, $10^4$ calls will be made to add and find methods.

Problem: Two Sum III - Data structure design

Easy

15 min

Statement

Design a data structure that takes in a stream of numbers and can check if any two numbers add up to a specific value.

Implement the TwoSum class with the following constructor and methods:

Constructor: Sets up the TwoSum object with an empty list at the start.
void add(int number): Adds a new number to the list.
boolean find(int value): Returns TRUE if any two numbers in the list add up to the given value. If not, it returns FALSE.

Constraints:

$-10^5 \leq$ number $\leq 10^5$
$-2^{31} \leq$ value $\leq 2^{31} -1$
At most, $10^4$ calls will be made to add and find methods.

Problem: Two Sum III - Data structure design

Statement

Examples

Understand the problem

Figure it out!

Try it yourself

Problem: Two Sum III - Data structure design

Statement

Examples

Understand the problem

Figure it out!

Try it yourself