Jump Game IV

HardGraphsbfs

Solve this the way you would in the interview: out loud, on a timer, with an AI interviewer asking follow-ups while you code. You get a scored report at the end.

Practice this as a mock interviewFree to start, no account needed

Problem

You start at index 0 of an integer array arr and want to reach the last index. From index i you can move in one step to: - i + 1 (if it is inside the array), - i - 1 (if it is inside the array), or - any index j != i with arr[j] == arr[i]. Return the minimum number of steps needed to reach the last index. Aim for O(n) time.

Examples

Input: arr = [100,-23,-23,404,100,23,23,23,3,404]
Output: 3
Go 0 -> 4 (both 100), 4 -> 3, then 3 -> 9 (both 404).
Input: arr = [7]
Output: 0
You already stand on the last index.
Input: arr = [7,6,9,6,9,6,9,7]
Output: 1
Jump straight from index 0 to index 7 since both hold 7.

Constraints

  • 1 <= arr.length <= 5 * 10^4
  • -10^8 <= arr[i] <= 10^8

What the interviewer grades

A correct solution is one of five scores. The report also grades problem understanding (did you clarify inputs and edge cases before coding), problem solving, communication while you work, code quality, and testing. See a sample report, or read up on the pattern in the lessons.

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