Cycle Shift

Problem Overview

• Count pairs (i, j) with i < j where two numbers have the same digit length and one can become the other via a cyclic shift of digits.
• Input: array of positive integers; Output: the total number of such cyclic pairs; Constraints: array length 1–100, values 1–10^4.
• Context: evaluates equality under digit rotations by moving ending digits to the front.
• Source: Asked in Ziprecruiter interviews; a classic coding interview interview question problem.