How should I practice Arithmetic Triplets After Queries?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Capital One online assessment problems in FastPrep.

Is Arithmetic Triplets After Queries associated with Capital One?

FastPrep tags this as a Capital One online assessment coding practice problem when the problem catalog has that company and stage context.

Arithmetic Triplets After Queries

Capital One● HardFULLTIMEOA

Learn

Problem statement

You are given an ordered array queries and a positive integer diff. Initially, a multiset of integers is empty.

+x adds one occurrence of integer x.
-x removes all occurrences of integer x. Removing an absent value changes nothing.

After each query, count the triples of occurrences whose values x, y, z satisfy x - y = y - z = diff. Each choice of occurrences counts separately, so a value triple contributes the product of its three frequencies. Return these counts in query order.

For this exercise, assume the first character of each query is the operation, and the remaining characters are a signed decimal integer with no spaces. For example, +-2 inserts negative two and --2 removes all negative twos. Counts use 64-bit integers.

Function

countArithmeticTriplets(queries: String[], diff: int) → long[]

Examples

Example 1

queries = ["+1","+3","+5","+5"]diff = 2return = [0,0,1,2]

The third query forms one triple with values 5, 3, 1. The fourth adds a second occurrence of 5, creating two choices for that occurrence.

Constraints

For this exercise, assume 0 <= queries.length <= 10^5.
For this exercise, assume -10^8 <= x <= 10^8 and 1 <= diff <= 10^8.
Every query has a valid operation followed by a valid signed decimal integer.
Use a signed 64-bit integer for each returned count.