Update MonotonicIncreasingStack.java

Author: NayanSaraff

src/test/java/com/thealgorithms/stacks/MonotonicIncreasingStack.java

@@ -10,84 +10,86 @@
  * https://www.geeksforgeeks.org/dsa/introduction-to-monotonic-stack-2/
  */
 
+package com.thealgorithms.stacks;
+
 import java.util.Stack;
 
 public final class MonotonicIncreasingStack {
 
-    private MonotonicIncreasingStack() {
-        throw new AssertionError("Cannot instantiate utility class");
-    }
+  private MonotonicIncreasingStack() {
+    throw new AssertionError("Cannot instantiate utility class");
+  }
 
-    /**
-     * Finds the next greater element for each element in the given array.
-     * 
-     * For each element, it returns the nearest greater element to its right.
-     * If no such element exists, -1 is returned for that index.
-     *
-     * Time Complexity: O(n)
-     * Space Complexity: O(n)
-     */
-    public static int[] nextGreaterElement(int[] arr) {
-        int n = arr.length;
-        int[] result = new int[n];
-        Stack<Integer> stack = new Stack<>();
+  /**
+   * Finds the next greater element for each element in the given array.
+   * For each element, it returns the nearest greater element to its right.
+   * If no such element exists, -1 is returned for that index.
+   *
+   * Time Complexity: O(n)
+   * Space Complexity: O(n)
+   */
+  public static int[] nextGreaterElement(int[] arr) {
+    int n = arr.length;
+    int[] result = new int[n];
+    Stack<Integer> stack = new Stack<>();
 
-        for (int i = n - 1; i >= 0; i--) {
-            while (!stack.isEmpty() && arr[i] >= arr[stack.peek()]) {
-                stack.pop();
-            }
-            result[i] = stack.isEmpty() ? -1 : arr[stack.peek()];
-            stack.push(i);
-        }
-        return result;
+    for (int i = n - 1; i >= 0; i--) {
+      while (!stack.isEmpty() && arr[i] >= arr[stack.peek()]) {
+        stack.pop();
+      }
+      result[i] = stack.isEmpty() ? -1 : arr[stack.peek()];
+      stack.push(i);
     }
+    return result;
+  }
 
-    /**
-     * Finds the next smaller element for each element in the given array.
-     *
-     * For each element, it returns the nearest smaller element to its right.
-     * If no such element exists, -1 is returned for that index.
-     *
-     * Time Complexity: O(n)
-     * Space Complexity: O(n)
-     */
-    public static int[] nextSmallerElement(int[] arr) {
-        int n = arr.length;
-        int[] result = new int[n];
-        Stack<Integer> stack = new Stack<>();
+  /**
+   * Finds the next smaller element for each element in the given array.
+   * For each element, it returns the nearest smaller element to its right.
+   * If no such element exists, -1 is returned for that index.
+   *
+   * Time Complexity: O(n)
+   * Space Complexity: O(n)
+   */
+  public static int[] nextSmallerElement(int[] arr) {
+    int n = arr.length;
+    int[] result = new int[n];
+    Stack<Integer> stack = new Stack<>();
 
-        for (int i = n - 1; i >= 0; i--) {
-            while (!stack.isEmpty() && arr[i] <= arr[stack.peek()]) {
-                stack.pop();
-            }
-            result[i] = stack.isEmpty() ? -1 : arr[stack.peek()];
-            stack.push(i);
-        }
-        return result;
+    for (int i = n - 1; i >= 0; i--) {
+      while (!stack.isEmpty() && arr[i] <= arr[stack.peek()]) {
+        stack.pop();
+      }
+      result[i] = stack.isEmpty() ? -1 : arr[stack.peek()];
+      stack.push(i);
     }
+    return result;
+  }
 
-    // Test class included in the same file
-    public static void main(String[] args) {
-        testScenario(new int[]{2, 5, 1, 3, 4});
-        testScenario(new int[]{1, 2, 3, 4, 5});
-        testScenario(new int[]{5, 4, 3, 2, 1});
-    }
+  // Test class included in the same file
+  public static void main(String[] args) {
+    testScenario(new int[]{2, 5, 1, 3, 4});
+    testScenario(new int[]{1, 2, 3, 4, 5});
+    testScenario(new int[]{5, 4, 3, 2, 1});
+  }
 
-    private static void testScenario(int[] arr) {
-        int[] nextGreater = nextGreaterElement(arr);
-        int[] nextSmaller = nextSmallerElement(arr);
+  private static void testScenario(int[] arr) {
+    int[] nextGreater = nextGreaterElement(arr);
+    int[] nextSmaller = nextSmallerElement(arr);
 
-        System.out.print("Array: ");
-        printArray(arr);
-        System.out.print("Next Greater: ");
-        printArray(nextGreater);
-        System.out.print("Next Smaller: ");
-        printArray(nextSmaller);
-        System.out.println("-----------------------------");
-    }
+    System.out.print("Array: ");
+    printArray(arr);
+    System.out.print("Next Greater: ");
+    printArray(nextGreater);
+    System.out.print("Next Smaller: ");
+    printArray(nextSmaller);
+    System.out.println("-----------------------------");
+  }
 
-    private static void printArray(int[] arr) {
-        for (int n : arr) System.out.print(n + " ");
-        System.out.println();
+  private static void printArray(int[] arr) {
+    for (int n : arr) {
+      System.out.print(n + " ");
     }
+    System.out.println();
+  }
 }