Counting Valleys | Python Solution | HackerRank

 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.

   View Solution :-   

   

#!/bin/python3

import math
import os
import random
import re
import sys

#
# Complete the 'countingValleys' function below.
#
# The function is expected to return an INTEGER.
# The function accepts following parameters:
#  1. INTEGER steps
#  2. STRING path
#

def countingValleys(steps, path):
    # Write your code here
    count=0
    dictt={"U":1,"D":-1}
    level=0
    for i in path:
        level=level+dictt[i]
        if(level==0 and i=="U"):
            count=count+1
            
    return(count)    

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    steps = int(input().strip())

    path = input()

    result = countingValleys(steps, path)

    fptr.write(str(result) + '\n')

    fptr.close()

Example 1 :-

Example 2 :-