Binary Search on Answer Technique in DSA C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main idea behind the Binary Search on Answer Technique?

It is a method to find an unknown value by guessing an answer range and using binary search to narrow down the correct answer based on a condition check.

beginner

In Binary Search on Answer, what does the 'answer' usually represent?

The 'answer' is the value we want to find, often a number like minimum or maximum that satisfies a given problem condition.

intermediate

Why do we use a condition function in Binary Search on Answer?

The condition function checks if a guessed answer is valid or not, helping us decide whether to search higher or lower in the answer range.

intermediate

How do you choose the initial search range in Binary Search on Answer?

You pick the smallest and largest possible values the answer can take, based on problem constraints or logical limits.

beginner

What is a real-life example where Binary Search on Answer can be applied?

Finding the minimum time needed to complete tasks when you can check if a given time is enough to finish all tasks.

What does Binary Search on Answer technique help you find?

A The middle element of an array

B An unknown value by narrowing down a range

C The sum of all elements in a list

D The maximum element in a sorted array

Binary Search on Answer narrows down the possible answer range to find the correct value.

Which of these is essential for Binary Search on Answer to work?

A Having a linked list

B Sorting the input array

C A condition function to check guesses

D Using recursion only

The condition function tells if the guessed answer is valid, guiding the search direction.

If the condition function returns true for a guess, what should you do next?

A Search for a smaller answer

B Search for a larger answer

C Stop immediately

D Ignore and guess randomly

If the guess is valid, try to find a smaller valid answer to optimize.

What is the time complexity of Binary Search on Answer if the condition check is O(n)?

A O(n^2)

B O(n)

C O(log n)

D O(n log m), where m is the answer range

Binary search runs in log m steps, each step doing O(n) work for condition check.

Which problem is a good candidate for Binary Search on Answer?

A Finding minimum maximum load to split tasks

B Sorting an array

C Finding duplicates in a list

D Reversing a string

Problems involving finding minimum or maximum values that satisfy conditions fit this technique.

Explain how Binary Search on Answer works step-by-step.

Think about guessing and checking answers like narrowing down a number.

Describe a problem scenario where Binary Search on Answer is useful and how you would apply it.

Consider tasks with time limits or capacity constraints.