Sorry, I made direct commit to my main branch, but no worries. I have…

… deleted it and than made another branch and made the commit. I have added 2 programs on Stack implementation using queue.

1]. DSA/1]. Data Structures/09]. Stack/C++/_03)_stack_using_2_queue_costly_pop_approach.cpp

@@ -0,0 +1,85 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class stackk
+	{
+		int n;
+		queue<int> q1;
+		queue<int> q2;
+
+		public:
+
+		stackk()
+			{
+				n = 0;
+			}
+
+		void push(int x)
+			{
+				q1.push(x);
+				n++;
+			}
+
+		void pop()
+			{
+				if(q1.empty())
+					{
+						cout<<"Empty Stack";
+						return;
+					}
+				while(q1.size()!=1)
+					{
+						q2.push(q1.front());
+						q1.pop();
+					}
+				q1.pop();
+				n--;
+				queue<int> temp = q1;
+				q1 = q2;
+				q2 = temp;
+			}
+
+		int top()
+			{
+				if(q1.empty())
+					{
+						cout<<"Empty Stack";
+						return -1;
+					}
+				while(q1.size()!=1)
+					{
+						q2.push(q1.front());
+						q1.pop();
+					}
+				int ans = q1.front();
+				q2.push(ans);
+				queue<int> temp = q1;
+				q1 = q2;
+				q2 = temp;
+				return ans;
+			}
+
+		int size(){return n;}
+
+	};
+
+int main()
+{
+	stackk s;
+	int n,x;
+	cin>>n;
+
+	for(int i=0;i<n;i++)
+		{
+			cin>>x;
+			s.push(x);
+		}
+
+	while(s.size()>0)
+		{
+			cout<<s.top()<<" ";
+			s.pop();
+		}
+
+	return 0;
+}

1]. DSA/1]. Data Structures/09]. Stack/C++/_04)_stack_using_2_queue_costly_push_approach.cpp

@@ -0,0 +1,67 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class stackk
+	{
+		int n;
+		queue<int> q1;
+		queue<int> q2;
+
+		public:
+
+		stackk()
+			{
+				n = 0;
+			}
+
+		void push(int x)
+			{
+				q2.push(x);
+				while(!q1.empty())
+					{
+						q2.push(q1.front());
+						q1.pop();
+					}
+				queue<int> temp = q1;
+				q1 = q2;
+				q2 = temp;
+				n++;
+			}
+
+		void pop()
+			{
+				if(q1.empty())
+					{
+						cout<<"Empty Stack";
+						return;
+					}
+				q1.pop();
+				n--;
+			}
+
+		int top(){	return q1.front();}
+
+		int size(){return n;}
+
+	};
+
+int main()
+{
+	stackk s;
+	int n,x;
+	cin>>n;
+
+	for(int i=0;i<n;i++)
+		{
+			cin>>x;
+			s.push(x);
+		}
+
+	while(s.size()>0)
+		{
+			cout<<s.top()<<" ";
+			s.pop();
+		}
+
+	return 0;
+}