Is Count Distinct Tags in a Fixed-Radius Circle (Practice Reconstruction) associated with Marshall Wace?

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

Count Distinct Tags in a Fixed-Radius Circle (Practice Reconstruction)

Q: How should I practice Count Distinct Tags in a Fixed-Radius Circle (Practice Reconstruction)?

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

Marshall Wace● EasyFULLTIMEOA

Problem statement

The inputs describe points with tags. Point i has tag S[i] and integer coordinates (X[i], Y[i]).

For this exercise, assume the circle is centred at (0,0), has the supplied fixed radius R, and includes its boundary. Records may share coordinates.

Count the different tags among points inside or on the circle. Count a tag only once, even if several points have that tag. Use the given radius; do not choose a different one.

Function

solution(S: String, X: int[], Y: int[], R: int) → int

Examples

Example 1

S = "ABAC"X = [1,2,-1,4]Y = [0,0,0,0]R = 2return = 2

This authored example encloses both A points and the B point. Their distinct tags are A and B; C lies outside.

Example 2

S = "AB"X = [3,3]Y = [4,5]R = 5return = 1

This authored example includes A exactly on the radius-five boundary. B is farther away and is excluded.

Example 3

S = "AAB"X = [0,0,0]Y = [0,0,0]R = 0return = 2

This authored example has a zero-radius circle and three records at its centre. Tags A and B contribute two distinct values.

Constraints

For this exercise, assume 0 <= S.length = X.length = Y.length <= 100000.
For this exercise, assume tags are uppercase English letters.
For this exercise, assume -10^9 <= X[i], Y[i] <= 10^9 and 0 <= R <= 10^9.