Is Minimum Rotations to Dial a Number I easy or hard?

It is rated Easy with a 75.8% acceptance rate. The main challenge is recognizing that the dial wraps around, so you must consider both directions. Once you see the min(d, 10 - d) pattern, the implementation takes only a few lines.

Minimum Rotations to Dial a Number I Python solution?

In Python, convert each character to an integer, keep a variable for the current position starting at 0, and for each digit compute d = abs(target - current), then add min(d, 10 - d) to the total. Return the total after the loop. The code is short and runs in O(n) time with O(1) extra space.

How to solve Minimum Rotations to Dial a Number I in O(n)?

Start the pointer at digit 0 and iterate through the target digits in order. For each digit, compute the absolute difference from the current position, take the smaller of that value and 10 minus that value, add it to the total, and set the current position to the target digit.

What is the best approach for Minimum Rotations to Dial a Number I?

The best approach is to compute the circular distance between each consecutive pair of digits using min(d, 10 - d), where d is the absolute difference. Sum these values while walking through the number once. This runs in O(n) time and O(1) space.

What data structure is used in Minimum Rotations to Dial a Number I?

No special data structure is required. The solution uses a few integer variables to track the current digit position and the running total. Simple iteration over the input string or digit array is enough.

What is the time complexity of Minimum Rotations to Dial a Number I?

The optimal solution runs in O(n) time, where n is the number of digits to dial, because each digit requires only constant-time arithmetic. The space complexity is O(1) since you only store the current position and a running total.

Is Minimum Rotations to Dial a Number I asked at Google, Amazon, or Meta?

This problem is tagged as General on FleetCode and does not have a specific company tag in our data. Check recent interview reports on company-specific sites before assuming it appears at a particular firm. The underlying skill, modular circular distance, is useful across many interview problems.

4070. Minimum Rotations to Dial a Number I - Practice Online

You are given a string s of length 10 consisting of digits.

The dial contains the digits 0 through 9 in order and is circular, so 0 and 9 are adjacent. The pointer initially points to 0.

To dial each digit of s in order, rotate the pointer until it points to that digit. Each rotation moves the pointer to an adjacent digit, and you may rotate in either direction. Dialing a digit that the pointer already points to requires no rotations.

Return the minimum total number of rotations needed to dial every digit of s.

Example 1:

Input: s = "0192837465"

Output: 25

Explanation:

Step	From	To	Rotations
1	0	0	0
2	0	1	1
3	1	9	2
4	9	2	3
5	2	8	4
6	8	3	5
7	3	7	4
8	7	4	3
9	4	6	2
10	6	5	1

The total is 0 + 1 + 2 + 3 + 4 + 5 + 4 + 3 + 2 + 1 = 25, which is the minimum total number of rotations.

Example 2:

Input: s = "1200210200"

Output: 12

Explanation:

Step	From	To	Rotations
1	0	1	1
2	1	2	1
3	2	0	2
4	0	0	0
5	0	2	2
6	2	1	1
7	1	0	1
8	0	2	2
9	2	0	2
10	0	0	0

The total is 1 + 1 + 2 + 0 + 2 + 1 + 1 + 2 + 2 + 0 = 12, which is the minimum total number of rotations.

Constraints:

s.length == 10
s consists only of digits '0' to '9'