Sort a stack

Author: sachuverma

DSA Crack Sheet/README.md

@@ -154,6 +154,7 @@
 - [Evaluation of Postfix Expression](https://practice.geeksforgeeks.org/problems/evaluation-of-postfix-expression1735/1# "view question") - [Cpp Solution](./solutions/Evaluation%20of%20Postfix%20Expression.cpp)
 - [Inserting at the end of stack](https://stackoverflow.com/questions/45130465/inserting-at-the-end-of-stack "view topic")
 - [Reverse a stack using recursion](https://www.geeksforgeeks.org/reverse-a-stack-using-recursion/ "view topic")
+- [Sort a stack](https://practice.geeksforgeeks.org/problems/sort-a-stack/1# "view question") - [Cpp Solution](./solutions/Sort%20a%20stack.cpp)
 - []( "view question") - [Cpp Solution](./solutions/.cpp)
 
 ### Heap

DSA Crack Sheet/solutions/Sort a stack.cpp

@@ -0,0 +1,50 @@
+/*
+Sort a stack
+============
+
+Given a stack, the task is to sort it such that the top of the stack has the greatest element.
+
+Example 1:
+Input:
+Stack: 3 2 1
+Output: 3 2 1
+
+Example 2:
+Input:
+Stack: 11 2 32 3 41
+Output: 41 32 11 3 2
+Your Task: 
+You don't have to read input or print anything. Your task is to complete the function sort() which sorts the elements present in the given stack. (The sorted stack is printed by the driver's code by popping the elements of the stack.)
+
+Expected Time Complexity : O(N*N)
+Expected Auixilliary Space : O(N) recursive.
+
+Constraints:
+1<=N<=100
+
+Note:The Input/Ouput format and Example given are used for system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from stdin/console. The task is to complete the function specified, and not to write the full code.
+*/
+
+void insert(stack<int> &s, int t)
+{
+  if (s.size() == 0 || s.top() < t)
+    s.push(t);
+  else
+  {
+    int temp = s.top();
+    s.pop();
+    insert(s, t);
+    s.push(temp);
+  }
+}
+
+void SortedStack ::sort()
+{
+  if (s.size() > 0)
+  {
+    int temp = s.top();
+    s.pop();
+    sort();
+    insert(s, temp);
+  }
+}