Fix typo in NextGraterElement (#4976)

src/main/java/com/thealgorithms/stacks/NextGreaterElement.java

@@ -0,0 +1,69 @@
+package com.thealgorithms.stacks;
+
+import java.util.Arrays;
+import java.util.Stack;
+
+/*
+    Given an array "input" you need to print the first greater element for each element.
+    For a given element x of an array, the Next greater element of that element is the
+    first greater element to the right side of it. If no such element is present print -1.
+
+    Example
+    input = { 2, 7, 3, 5, 4, 6, 8 };
+    At i = 0
+    Next greater element between (1 to n) is 7
+    At i = 1
+    Next greater element between (2 to n) is 8
+    At i = 2
+    Next greater element between (3 to n) is 5
+    At i = 3
+    Next greater element between (4 to n) is 6
+    At i = 4
+    Next greater element between (5 to n) is 6
+    At i = 5
+    Next greater element between (6 to n) is 8
+    At i = 6
+    Next greater element between (6 to n) is -1
+
+    result : [7, 8, 5, 6, 6, 8, -1]
+
+    1. If the stack is empty Push an element in the stack.
+    2. If the stack is not empty:
+        a.  compare the top element of the stack with next.
+        b.  If next is greater than the top element, Pop element from the stack.
+            next is the next greater element for the popped element.
+        c.  Keep popping from the stack while the popped element is smaller
+            than next. next becomes the next greater element for all such
+            popped elements.
+        d. Finally, push the next in the stack.
+
+    3. If elements are left in stack after completing while loop then their Next greater element is
+   -1.
+ */
+
+public class NextGreaterElement {
+
+    public static int[] findNextGreaterElements(int[] array) {
+        if (array == null) {
+            return array;
+        }
+
+        int[] result = new int[array.length];
+        Stack<Integer> stack = new Stack<>();
+
+        for (int i = 0; i < array.length; i++) {
+            while (!stack.isEmpty() && array[stack.peek()] < array[i]) {
+                result[stack.pop()] = array[i];
+            }
+            stack.push(i);
+        }
+
+        return result;
+    }
+
+    public static void main(String[] args) {
+        int[] input = {2, 7, 3, 5, 4, 6, 8};
+        int[] result = findNextGreaterElements(input);
+        System.out.println(Arrays.toString(result));
+    }
+}