IBM | OA | Extraordinary Substring

Round 1

Questions: Given a string, count its total number of non-empty extraordinary substrings. An extraordinary substring is one whose sum of the mapped values of each letter is divisible by its length.

| String | Mapped | Sum | Length | IsDivisible | |--------|--------|-----|--------|-------------| | a | 1 | 1 | 1 | Yes | | s | 7 | 7 | 1 | Yes | | d | 2 | 2 | 1 | Yes | | f | 3 | 3 | 1 | Yes | | as | 1,7 | 8 | 2 | Yes | | sd | 7,2 | 9 | 2 | No | | df | 2,3 | 5 | 2 | No | | asd | 1,7,2 | 10 | 3 | No | | sdf | 7,2,3 | 12 | 3 | Yes | | asdf | 1,7,2,3| 13 | 4 | No |

There are 6 extraordinary substrings.

Function
countSubstrings has the following parameter(s):
string input_str: a string of length n

Returns
int: the number of non-empty extraordinary substrings

Constraints

• 1 <= n <= 2000
• All characters of input_str are lowercase English letters.

Sample Case 0
Input: bdh
Output: 4
Explanation:
The extraordinary substrings are 'b', 'd', 'h', and 'bdh'.

Sample Case 1
Input: abcd
Output: 6
Explanation:
The extraordinary substrings are 'a', 'b', 'c', 'd', 'ab', and 'cd'.