HackerRank Problem #20

Weighted Uniform Strings

riaevnt

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Feb 7, 2025

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Problem

A weighted string is a string of lowercase English letters where each letter has a weight. Character weights are 1 to 26 from a to z as shown below:

• The weight of a string is the sum of the weights of its characters. For example:
• A uniform string consists of a single character repeated zero or more times. For example, ccc and a are uniform strings, but bcb and cd are not.

Given a string, s, let 𝑈 be the set of weights for all possible uniform contiguous substrings of string s. There will be n queries to answer where each query consists of a single integer. Create a return array where for each query, the value is Yes if query[i] ∈ 𝑈. Otherwise, append No.

Note: The ∈ symbol denotes that x[i] is an element of set 𝑈.

Example

s = ‘abbcccdddd’

queries = [1, 7, 5, 4, 15].

Working from left to right, weights that exist are:

string  weight
a       1
b       2
bb      4
c       3
cc      6
ccc     9
d       4
dd      8
ddd     12
dddd    16

Now for each value in queries, see if it exists in the possible string weights. The return array is ['Yes', 'No', 'No', 'Yes', 'No'].