What is the optimal time complexity of solving Finding Number of times x digit occurs?

The optimized solution achieves a time complexity of O(n) by using sorting, mathematical shortcuts, or hash table lookups.

What is the auxiliary space complexity for Finding Number of times x digit occurs?

The space complexity is O(1) since we only use a minimal/constant amount of extra memory for tracking variables (or auxiliary space if dynamic structures are allocated).

What are the typical edge cases we must handle in Finding Number of times x digit occurs?

Key edge cases include empty collections, negative or large bounds causing integer overflow, arrays with only one element, or inputs where target criteria are not met.

How can we optimize the brute force approach for Finding Number of times x digit occurs?

Brute force methods often inspect all possible combinations. We optimize this by sorting the input list to enable binary search, or tracking processed items in a set to avoid redundant nested loop lookups.

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Finding Number of times x digit occurs

Learn how to solve the 'Finding Number of times x digit occurs' problem. This detailed resource details brute force and optimized approaches.

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Problem Statement

Easy

Write a function count_digit(n, x) that takes a non-negative integer n and a digit x (0-9), and returns the number of times digit x appears in n.

For example, in the number 122333, the digit 3 appears 3 times.

Constraints

•0 <= n <= 10^9
•0 <= x <= 9

Examples

Example 1

Input

count_digit(122333, 3)

Output

Explanation

The digits of 122333 are 1,2,2,3,3,3. The digit 3 appears 3 times.

Example 2

Input

count_digit(1000, 0)

Output

Explanation

The digits of 1000 are 1,0,0,0. The digit 0 appears 3 times.

Example 3

Input

count_digit(12345, 6)

Output

Explanation

The digit 6 does not appear in 12345.

Need a Hint?

Use simple arithmetic operators (like modulo `%`, division `//`), conditional checks, or loops to inspect number properties.

Edge Cases to Watch

Empty list or null input variables
Single item lists/arrays
Extremely large input bounds causing integer or stack overflow

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