fix: counting Valleys

CountValleys/CountingValleys.java

@@ -0,0 +1,112 @@
+import java.util.Scanner;
+
+/**
+ * CountingValleys
+ * 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.
+ * BlogScoringEnvironmentFAQAbout UsSupportCareersTerms Of ServicePrivacy Policy
+ */
+public class CountingValleys {
+
+  // /\
+  // _ / \_
+  // \ /
+  // \/
+
+  public static void main(String[] args) {
+    System.out.println("Please enter the number of steps: ");
+    Scanner sc = new Scanner(System.in);
+    int steps = sc.nextInt();
+    sc.nextLine(); // consume the newline
+
+    System.out.println("The hiker is taking " + steps + " steps starting from sea level.");
+    System.out.println("Please enter the path (U for up, D for down):");
+    String path = sc.nextLine();
+
+    sc.close();
+    System.out.println("Number of valleys: " + countingHikeValleys(steps, path));
+  }
+
+  private static int countingHikeValleys(int steps, String path) {
+    int valleysCount = 0;
+    int seaLevel = 0;
+    boolean inValley = false;
+
+    for (char step : path.toCharArray()) {
+      if (Character.toUpperCase(step) == 'U') {
+        seaLevel++;
+      } else if (Character.toUpperCase(step) == 'D') {
+        seaLevel--;
+      }
+
+      // If we're below sea level and weren't before, we're entering a valley
+      if (seaLevel < 0 && !inValley) {
+        valleysCount++;
+        inValley = true;
+      }
+      // If we're at or above sea level, we're no longer in a valley
+      if (seaLevel >= 0) {
+        inValley = false;
+      }
+    }
+
+    return valleysCount;
+  }
+}