Moved StackPostfixNotation.java from the Others section to the Stack section (#4372)

* Moved StackPostfixNotation.java from the Others section to the Stack section

* Put all stack related algo in a separate stack directory in the algorithms directory. The stack directory under data-structures now only contains various implementations of the stack data structure.

* formatted files

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Stack;
 

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

@@ -7,7 +7,7 @@
  * Program description - Given an integer array. The task is to find the maximum of the minimum of
  * the array
  */
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.*;
 

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Stack;
 

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 //  1. You are given a string exp representing an expression.
 // 2. Assume that the expression is balanced  i.e. the opening and closing brackets match with each

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Stack;
 

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Stack;
 

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Arrays;
 import java.util.Stack;

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Arrays;
 import java.util.Stack;

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Arrays;
 import java.util.Stack;

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.datastructures.stacks;
+package com.thealgorithms.stacks;
 
 import java.util.Stack;
 

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

@@ -1,4 +1,4 @@
-package com.thealgorithms.others;
+package com.thealgorithms.stacks;
 
 import java.util.Scanner;
 import java.util.Stack;