Interview Questions/Coding/Count Valid Modulo Partitions

Count Valid Modulo Partitions

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Medium

Count Valid Modulo Partitions

You are given an array nums. For every positive divisor k of nums.length, split the array into consecutive parts of length k. A value k is valid if there exists an integer m >= 2 such that after replacing every number with its remainder modulo m, all parts become identical. Return the number of valid values of k.

Examples

Example 1
Input:
1 2 1 2
Output:
2

Explanation: k = 2 and k = 4 are valid.

Approach hint

For a fixed k, compare elements that are in the same position inside different blocks.

Common mistake

Skipping assumptions, edge cases, or trade-offs can make an otherwise good answer feel incomplete.

solution.cpp