**Counting Valleys**

### Problem Statement :

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: 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 steps = 8 path = [DDUUUUDD] The hiker first enters a valley 2 units deep. Then they climb out and up onto a mountain 2 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 steps, the number of steps in the hike. The second line contains a single string path, of steps characters that describe the path. Constraints 2 <= steps <= 10^6 path[i] belongs to {U, D}

### Solution :

` ````
Solution in C :
python 3 :
N=int(input())
S=input()
L=0
V=0
for s in S:
if s == 'U':
L += 1
if L == 0:
V += 1
else:
L -= 1
print(V)
Java :
import java.io.*;
import java.util.*;
public class Solution {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
in.nextInt();
String s = in.next();
int level = 0;
int valleys = 0;
for(int i = 0; i < s.length(); i++){
if(s.charAt(i) == 'U'){
level++;
}else if(s.charAt(i) == 'D'){
if(level == 0){
valleys++;
}
level--;
}
}
System.out.println(valleys);
}
}
C++ :
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int l;
string str; cin>>l>>str;
int height = 0;
int count = 0;
for(int i=0;i<l;i++){
if (str[i]=='U') height++;
else {
if (height==0) count++;
height--;
}
}
if (height<0) count--;
cout<<count<<endl;
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
return 0;
}
C :
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
int main() {
int n;
scanf("%i", &n);
char str[n];
scanf("%s", str);
int level = 0, result = 0, valley = 0;
for (int i = 0; i < n; i++) {
if(str[i] == 'U') {
level++;
if(level == 0 && valley) {
valley = 0;
result++;
}
}
else if(str[i] == 'D') {
if(level == 0)
valley = 1;
level--;
}
}
printf("%i", result);
return 0;
}
```

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