43. Steady Trend
A weather station logs a reading once an hour and stores the readings in values. The log is called steady if it never changes direction: either no reading is lower than the one before it (it only rises or stays level), or no reading is higher than the one before it (it only falls or stays level).
Return true if the log is steady and false otherwise. A log with one reading, or with all readings equal, is steady.
Solve it in a single pass over the array, without sorting or copying it.
Example 1
- Input:
- values = [1,2,2,5]
- Output:
- true
- Explanation:
No reading ever drops, so the log is steady.
Example 2
- Input:
- values = [6,4,5,1]
- Output:
- false
- Explanation:
The log falls, rises and falls again, so it is not steady.
Example 3
- Input:
- values = [3,3,3]
- Output:
- true
- Explanation:
All readings are equal, so the log is steady.
Constraints
1 ≤ values.length ≤ 105
-109 ≤ values[i] ≤ 109
How this problem is judged
- Answers
- Your answer must match exactly. Numbers compare by value, so 2 and 2.0 are equal.
Expected complexity
- Time
- O(n)
- Space
- O(1)