Problem: Two Sum III - Data structure design

Medium

30 min

Explore how to design and implement a TwoSum data structure that supports adding numbers and finding if any pair sums to a given value. This lesson helps you understand custom data structures useful for interview coding patterns, enabling efficient add and find operations while managing constraints on input size and value range.

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

Medium

30 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