PracticeArrays

Is the Score Run Steady?

EasyArraystraversalaccumulationstate tracking Time not estimated Not started

Context

In the arcade game Neon Vault, a player’s score is recorded after each level. The game designer wants to detect whether the run progressed steadily: a later score may match an earlier score, but it must never be lower. This helps identify score histories that follow the expected progression.

Problem

Write a function that checks whether the scores in a Neon Vault run are nondecreasing from first to last. A run is valid when no score is greater than any score appearing after it. Equal scores are allowed. Return False as soon as a later score is smaller than the greatest score seen earlier; otherwise return True after the entire list has been checked. An empty or one-score run is valid because it contains no out-of-order pair. Use linear time and constant extra space.

Examples

Example 1

Input: scores = []

Output: True

Explanation: The empty list returns True because an empty run is valid; the final values include is_valid=true and scan_index=0. (fact_ids:,, )

Example 2

Input: scores = [12, 12, 15, 15, 21]

Output: True

Explanation: The list [12, 12, 15, 15, 21] returns True, and the trace ends with is_valid=true, prefix_peak=21, and scan_index=5. (fact_ids:, )

Example 3

Input: scores = [4, 9, 7, 10]

Output: False

Explanation: The list [4, 9, 7, 10] returns False because its trace ends with is_valid=false after scan_index=2 and prefix_peak=9. (fact_ids:, )

Constraints

0 <= len(scores) <= 100000
-1000000 <= scores[i] <= 1000000 for every i
Types: scores is int[]; result is bool

Function signature

def is_steady_score_run(scores: list[int]) -> bool

scores list[int]: Scores recorded in level order.
returns bool: True when the score sequence never decreases relative to its earlier maximum; otherwise False.

Adapted from MBPP problem task_303 (CC BY 4.0). Rewritten, extended and verified by Iksha.

Notes

An empty run is valid.
Duplicate scores are allowed.
The scan may stop at the first violation.

Code

Saved

Checking environment…Python SandboxLn 1, Col 1

scores =