Maximum Later Checkpoint Altitude Gain
Yellow.ai● EasyFULLTIMEPHONE SCREENProblem statement
A trek records checkpoint altitudes in their visit order in trek. Choose one checkpoint and a strictly later checkpoint. Return the largest positive later altitude minus earlier altitude.
The checkpoints need not be adjacent. Return 0 when no positive gain is possible, including when there are fewer than two checkpoints. Return the exact result as a 64-bit integer.
Function
maximumAltitudeGain(trek: int[]) → longExamples
Example 1
trek = [1000,1200,800,1175,700,1500]return = 800Checkpoint 4 has altitude 700 and the later checkpoint 5 has altitude 1500. Their gain is 800, the largest among all 15 ordered checkpoint pairs. The source printed 700; that conflicting line is not the judged result.
Example 2
trek = [9,7,4,1]return = 0Every later checkpoint is lower, so there is no positive gain and the result is 0.
Constraints
0 <= trek.length <= 100000.-2147483648 <= trek[i] <= 2147483647.