Kadane's Algorithm Maximum Subarray in DSA C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What problem does Kadane's Algorithm solve?

Kadane's Algorithm finds the maximum sum of a contiguous subarray within a one-dimensional array of numbers.

beginner

What is the main idea behind Kadane's Algorithm?

It keeps track of the current subarray sum and resets it to zero if it becomes negative, while updating the maximum sum found so far.

intermediate

In Kadane's Algorithm, what does the variable 'current_sum' represent?

'current_sum' represents the sum of the current subarray being considered. It resets when the sum becomes negative to start fresh from the next element.

intermediate

Why does Kadane's Algorithm reset the current sum to zero when it becomes negative?

Because a negative sum will only decrease the sum of any future subarray, so it's better to start a new subarray from the next element.

beginner

What is the time complexity of Kadane's Algorithm?

Kadane's Algorithm runs in O(n) time, where n is the number of elements in the array, because it processes each element once.

What does Kadane's Algorithm return?

A Maximum sum of a contiguous subarray

B Minimum sum of a contiguous subarray

C Sum of all elements in the array

D Length of the longest subarray

Kadane's Algorithm finds the maximum sum of any contiguous subarray.

When does Kadane's Algorithm reset the current sum to zero?

A When current sum is positive

B When current sum is zero

C When current sum is negative

D Never resets

It resets current sum to zero when it becomes negative to avoid reducing future sums.

What is the initial value of the maximum sum in Kadane's Algorithm?

A Sum of all elements

B First element of the array

C 0

D Negative infinity or very small number

Maximum sum starts very low to ensure any subarray sum will update it.

What is the time complexity of Kadane's Algorithm?

A O(n)

B O(n log n)

C O(n^2)

D O(log n)

Kadane's Algorithm processes each element once, so it runs in linear time O(n).

Which of these is NOT true about Kadane's Algorithm?

A It uses a running sum and maximum sum variables

B It works only for arrays with positive numbers

C It finds the maximum sum of contiguous subarray

D It can handle negative numbers

Kadane's Algorithm works for arrays with negative numbers as well.

Explain how Kadane's Algorithm finds the maximum sum of a contiguous subarray.

Think about how you decide to keep or drop a subarray while moving through the array.

Describe the role of the variables used in Kadane's Algorithm and how they change during execution.

Focus on how current sum and maximum sum interact as you scan the array.