Counting Valleys HackerRank Problem Solution

Counting Valleys Hacker Rank Problem Solution

In this Counting Valleys HackerRank Problem, An avid hiker keeps meticulous records of their hikes. During the last hike that took exactly  steps, for every step it was noted if it was an uphill, or a downhill step. Hikes always start and end at sea level, and each step up or down represents a  unit change in altitude. We define the following terms:

  • 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.
  • 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

 

The hiker first enters a valley  units deep. Then they climb out and up onto a mountain  units high. Finally, the hiker returns to sea level and ends the hike.

Function Description

Complete the countingValleys function in the editor below.

countingValleys has the following parameter(s):

  • int steps: the number of steps on the hike
  • string path: a string describing the path

Returns

  • int: the number of valleys traversed

Input Format

The first line contains an integer , the number of steps in the hike.
The second line contains a single string , of  characters that describe the path.

Constraints

Sample Input

8
UDDDUDUU

Sample Output

1

Explanation

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 one valley.

Counting Valleys Hacker Rank Problem Solutions

I will Provide solution in Multiple programming languages for you. If you are not able to find the code in required language then please share in comments so that our team can help you.

Problem Solution in JavaScript

function countingValleys(steps, path) {
  let seaLevel = 0;
  let pathArr = [];
  let valley = 0;


  for (let i = 0; i < steps; i++) {
    if (path[i] === 'U') {
      seaLevel += 1;
      if(seaLevel === 0){
        valley++;
      }
    } else if (path[i] === 'D') {
      seaLevel -= 1;
    }
    pathArr.push(seaLevel);
  }
  return valley;
}

Problem Solution in Python

def countingValleys(steps, path):
    level = 0
    ans = 0
    for i in range(steps):
        if path[i] == 'U':
            level += 1
            if level == 0:
                ans += 1
        elif path[i] == 'D':
            level += -1
    return ans

Problem Solution in Java

public static int countingValleys(int steps, String path) {
    // Write your code here
        int i =0, temp =0,count=0,a=0;
       
        while(i<steps){
            if(path.charAt(i) == 'D'){
                a = a - 1;
            }else{
                a += 1;
            }
            if(a<0){
                temp = 1;
            }
            if(temp == 1 && a == 0){
                count++;
                temp =0;
            }
            i++;
        }
        return count;
    }