Hackerank: Test Challenge — Counting Valleys.
2 min readJan 8, 2021
Hello Friends, welcome back to my channel, we are going to be solving a Hackerank problem today. Without much ado, lets’ get right to it. Quick Info, I would appreciate you understand the problem before going through the solution, also I have made available this solution in Javascript and PHP.
Problem
An avid hiker keeps meticulous records of their hikes. During the last hike that took exactly steps steps, for every step, it was noted if it was an uphill, U, or a downhill, D step. Hikes always start and end at sea level, and each step up or down represents a 1 unit change in altitude. We define the following terms:n: A mountain is a sequence of consecutive steps above sea level, starting with a step up from sea level and ending with a step down to sea level.n: A valley is a sequence of consecutive steps below sea level, starting with a step down from sea level and ending with a step up to sea level.Given the sequence of up and down steps during a hike, find and print the number of valleys walked through.
Example
steps = 8 path = [DDUUUUDD]The hiker first enters a valley 2 units deep. Then they climb out and up unto a mountain 2 units high. Finally the hiker returns to sea level and ends the hike.
Function Description
Complete the countingValley function i the editor below.
countingValleys has the following parametes(s):n: int steps: the number of steps on the hike.
n: string path: a string describing the path
Returns
int: the number of valleys traveredInput Format
The first line contains an integer steps, the number of steps in the hike.
The second line contains a single string path, or steps characters that describes the path.Sample Input
8
UDDDUDUUSample Output
1Explanation
If we represent _ as sea level, a step up as /, and a step down as \, the hike can be drawn as:_/\ _
\ /
\/\/The hiker enters and leaves on valley
The solution in Javascript(NodeJs).
The solution in PHP
Solution in Dart
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