Sub Array Sum

This algorithm aims at finding sub arrays (continuous elements) in an array have sum of its element as k. It uses mathematical properties of numbers to generate the answer quicker.

Finds the answer using one pass

Brut force does it in $O(N²)$ but this algorithm does the same in $O(N)$.

It uses an Hash Map to store the previous calculated prefix sums.

Kadane Algorithm

This looks pretty similar to the sub array sum problem but this is actually different. Here, it's about finding the maximum possible sub array sum.

• Used to find a continuous segment where there is maximum value.
• Used for any problem where continuous elements is a requirement.

Restarts the sum calculation based on condition

If the adding the new element to the previous sum makes the sum lower than the element itself, then we star a new array from that element.