diff --git a/data_structures/CMakeLists.txt b/data_structures/CMakeLists.txt
index fab3c5642..6c0555148 100644
--- a/data_structures/CMakeLists.txt
+++ b/data_structures/CMakeLists.txt
@@ -18,5 +18,3 @@ foreach( testsourcefile ${APP_SOURCES} )
 endforeach( testsourcefile ${APP_SOURCES} )
 
 add_subdirectory(cll)
-add_subdirectory(queue)
-add_subdirectory(stk)
diff --git a/data_structures/queue.h b/data_structures/queue.h
new file mode 100644
index 000000000..ed97a1e8d
--- /dev/null
+++ b/data_structures/queue.h
@@ -0,0 +1,88 @@
+/* This class specifies the basic operation on a queue as a linked list */
+#ifndef DATA_STRUCTURES_QUEUE_QUEUE_H_
+#define DATA_STRUCTURES_QUEUE_QUEUE_H_
+
+#include <cassert>
+#include <iostream>
+
+/** Definition of the node */
+template <class Kind>
+struct node {
+    Kind data;
+    node<Kind> *next;
+};
+
+/** Definition of the queue class */
+template <class Kind>
+class queue {
+ public:
+    /** Show queue */
+    void display() {
+        node<Kind> *current = queueFront;
+        std::cout << "Front --> ";
+        while (current != NULL) {
+            std::cout << current->data << "    ";
+            current = current->next;
+        }
+        std::cout << std::endl;
+        std::cout << "Size of queue: " << size << std::endl;
+    };
+
+    /** Default constructor*/
+    queue() {
+        queueFront = NULL;
+        queueRear = NULL;
+        size = 0;
+    };
+
+    /** Destructor */
+    ~queue(){};
+
+    /** Determine whether the queue is empty */
+    bool isEmptyQueue() { return (queueFront == NULL); };
+
+    /** Add new item to the queue */
+    void enQueue(Kind item) {
+        node<Kind> *newNode;
+        newNode = new node<Kind>;
+        newNode->data = item;
+        newNode->next = NULL;
+        if (queueFront == NULL) {
+            queueFront = newNode;
+            queueRear = newNode;
+        } else {
+            queueRear->next = newNode;
+            queueRear = queueRear->next;
+        }
+        size++;
+    };
+
+    /** Return the first element of the queue */
+    Kind front() {
+        assert(queueFront != NULL);
+        return queueFront->data;
+    };
+
+    /** Remove the top element of the queue */
+    void deQueue() {
+        node<Kind> *temp;
+        if (!isEmptyQueue()) {
+            temp = queueFront;
+            queueFront = queueFront->next;
+            delete temp;
+            size--;
+        } else {
+            std::cout << "Queue is empty !" << std::endl;
+        }
+    };
+
+    /** Clear queue */
+    void clear() { queueFront = NULL; };
+
+ private:
+    node<Kind> *queueFront; /**< Pointer to the front of the queue */
+    node<Kind> *queueRear;  /**< Pointer to the rear of the queue  */
+    int size;
+};
+
+#endif  // DATA_STRUCTURES_QUEUE_QUEUE_H_
diff --git a/data_structures/queue/CMakeLists.txt b/data_structures/queue/CMakeLists.txt
deleted file mode 100644
index 434d3bb45..000000000
--- a/data_structures/queue/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-add_library(libqueue OBJECT queue.h queue.cpp)
-add_executable( test_queue 
-    test_queue.cpp 
-)
-target_link_libraries(test_queue PUBLIC libqueue)
-
-install(TARGETS test_queue DESTINATION "bin/data_structures")
diff --git a/data_structures/queue/queue.cpp b/data_structures/queue/queue.cpp
deleted file mode 100644
index 9d5f9b9df..000000000
--- a/data_structures/queue/queue.cpp
+++ /dev/null
@@ -1,83 +0,0 @@
-#include "./queue.h"
-
-#include <cassert>
-#include <iostream>
-
-/* Default constructor*/
-template <class Kind>
-queue<Kind>::queue() {
-    queueFront = NULL;
-    queueRear = NULL;
-    size = 0;
-}
-
-/* Destructor */
-template <class Kind>
-queue<Kind>::~queue() {}
-
-/* Display for testing */
-template <class Kind>
-void queue<Kind>::display() {
-    node<Kind> *current = queueFront;
-    std::cout << "Front --> ";
-    while (current != NULL) {
-        std::cout << current->data << "    ";
-        current = current->next;
-    }
-    std::cout << std::endl;
-    std::cout << "Size of queue: " << size << std::endl;
-}
-
-/* Determine whether the queue is empty */
-template <class Kind>
-bool queue<Kind>::isEmptyQueue() {
-    return (queueFront == NULL);
-}
-
-/* Clear queue */
-template <class Kind>
-void queue<Kind>::clear() {
-    queueFront = NULL;
-}
-
-/* Add new item to the queue */
-template <class Kind>
-void queue<Kind>::enQueue(Kind item) {
-    node<Kind> *newNode;
-    newNode = new node<Kind>;
-    newNode->data = item;
-    newNode->next = NULL;
-    if (queueFront == NULL) {
-        queueFront = newNode;
-        queueRear = newNode;
-    } else {
-        queueRear->next = newNode;
-        queueRear = queueRear->next;
-    }
-    size++;
-}
-
-/* Return the top element of the queue */
-template <class Kind>
-Kind queue<Kind>::front() {
-    assert(queueFront != NULL);
-    return queueFront->data;
-}
-
-/* Remove the element of the queue */
-template <class Kind>
-void queue<Kind>::deQueue() {
-    node<Kind> *temp;
-    if (!isEmptyQueue()) {
-        temp = queueFront;
-        queueFront = queueFront->next;
-        delete temp;
-        size--;
-    } else {
-        std::cout << "Queue is empty !" << std::endl;
-    }
-}
-
-#include <string>
-/** force instantiate to export the type class */
-template class queue<std::string>;
diff --git a/data_structures/queue/queue.h b/data_structures/queue/queue.h
deleted file mode 100644
index d55ee3864..000000000
--- a/data_structures/queue/queue.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/* This class specifies the basic operation on a queue as a linked list */
-#ifndef DATA_STRUCTURES_QUEUE_QUEUE_H_
-#define DATA_STRUCTURES_QUEUE_QUEUE_H_
-
-/** Definition of the node */
-template <class Kind>
-struct node {
-    Kind data;
-    node<Kind> *next;
-};
-
-/** Definition of the queue class */
-template <class Kind>
-class queue {
- public:
-    void display();          /**< Show queue */
-    queue();                 /**< Default constructor*/
-    ~queue();                /**< Destructor */
-    bool isEmptyQueue();     /**< Determine whether the queue is empty */
-    void enQueue(Kind item); /**< Add new item to the queue */
-    Kind front();            /**< Return the first element of the queue */
-    void deQueue();          /**< Remove the top element of the queue */
-    void clear();
-
- private:
-    node<Kind> *queueFront; /**< Pointer to the front of the queue */
-    node<Kind> *queueRear;  /**< Pointer to the rear of the queue  */
-    int size;
-};
-
-#endif  // DATA_STRUCTURES_QUEUE_QUEUE_H_
diff --git a/data_structures/stack.h b/data_structures/stack.h
new file mode 100644
index 000000000..7b50e1f67
--- /dev/null
+++ b/data_structures/stack.h
@@ -0,0 +1,111 @@
+/* This class specifies the basic operation on a stack as a linked list */
+#ifndef DATA_STRUCTURES_STK_STACK_H_
+#define DATA_STRUCTURES_STK_STACK_H_
+
+#include <cassert>
+#include <iostream>
+
+/* Definition of the node */
+template <class Type>
+struct node {
+    Type data;
+    node<Type> *next;
+};
+
+/* Definition of the stack class */
+template <class Type>
+class stack {
+ public:
+    /** Show stack */
+    void display() {
+        node<Type> *current = stackTop;
+        std::cout << "Top --> ";
+        while (current != NULL) {
+            std::cout << current->data << "  ";
+            current = current->next;
+        }
+        std::cout << std::endl;
+        std::cout << "Size of stack: " << size << std::endl;
+    };
+
+    /** Default constructor*/
+    stack() {
+        stackTop = NULL;
+        size = 0;
+    };
+
+    /** Destructor */
+    ~stack(){};
+
+    /** Determine whether the stack is empty */
+    bool isEmptyStack() { return (stackTop == NULL); };
+
+    /** Add new item to the stack */
+    void push(Type item) {
+        node<Type> *newNode;
+        newNode = new node<Type>;
+        newNode->data = item;
+        newNode->next = stackTop;
+        stackTop = newNode;
+        size++;
+    };
+
+    /** Return the top element of the stack */
+    Type top() {
+        assert(stackTop != NULL);
+        return stackTop->data;
+    };
+
+    /** Remove the top element of the stack */
+    void pop() {
+        node<Type> *temp;
+        if (!isEmptyStack()) {
+            temp = stackTop;
+            stackTop = stackTop->next;
+            delete temp;
+            size--;
+        } else {
+            std::cout << "Stack is empty !" << std::endl;
+        }
+    };
+
+    /** Clear stack */
+    void clear() { stackTop = NULL; };
+
+    /** Overload "=" the assignment operator */
+    stack<Type> &operator=(const stack<Type> &otherStack) {
+        node<Type> *newNode, *current, *last;
+
+        /* If stack is no empty, make it empty */
+        if (stackTop != NULL) {
+            stackTop = NULL;
+        }
+        if (otherStack.stackTop == NULL) {
+            stackTop = NULL;
+        } else {
+            current = otherStack.stackTop;
+            stackTop = new node<Type>;
+            stackTop->data = current->data;
+            stackTop->next = NULL;
+            last = stackTop;
+            current = current->next;
+            /* Copy the remaining stack */
+            while (current != NULL) {
+                newNode = new node<Type>;
+                newNode->data = current->data;
+                newNode->next = NULL;
+                last->next = newNode;
+                last = newNode;
+                current = current->next;
+            }
+        }
+        size = otherStack.size;
+        return *this;
+    };
+
+ private:
+    node<Type> *stackTop; /**< Pointer to the stack */
+    int size;
+};
+
+#endif  // DATA_STRUCTURES_STK_STACK_H_
diff --git a/data_structures/stk/CMakeLists.txt b/data_structures/stk/CMakeLists.txt
deleted file mode 100644
index 30149ec06..000000000
--- a/data_structures/stk/CMakeLists.txt
+++ /dev/null
@@ -1,15 +0,0 @@
-add_library(libstack OBJECT stack.h stack.cpp)
-add_executable( stack 
-    main.cpp 
-)
-target_link_libraries(stack PUBLIC libstack)
-# set_target_properties(stack PROPERTIES LINKER_LANGUAGE CXX)
-
-add_executable( test_stack  
-    test_stack.cpp 
-)
-target_link_libraries(test_stack PUBLIC libstack)
-
-install(TARGETS stack DESTINATION "bin/data_structures")
-install(TARGETS test_stack DESTINATION "bin/data_structures")
-install(FILES students.txt DESTINATION "bin/data_structures")
diff --git a/data_structures/stk/stack.cpp b/data_structures/stk/stack.cpp
deleted file mode 100644
index 23aa3c05a..000000000
--- a/data_structures/stk/stack.cpp
+++ /dev/null
@@ -1,109 +0,0 @@
-#include "./stack.h"
-
-#include <cassert>
-#include <iostream>
-
-/* Default constructor*/
-template <class Type>
-stack<Type>::stack() {
-    stackTop = NULL;
-    size = 0;
-}
-
-/* Destructor */
-template <class Type>
-stack<Type>::~stack() {}
-
-/* Display for testing */
-template <class Type>
-void stack<Type>::display() {
-    node<Type> *current = stackTop;
-    std::cout << "Top --> ";
-    while (current != NULL) {
-        std::cout << current->data << "  ";
-        current = current->next;
-    }
-    std::cout << std::endl;
-    std::cout << "Size of stack: " << size << std::endl;
-}
-
-/* Determine whether the stack is empty */
-template <class Type>
-bool stack<Type>::isEmptyStack() {
-    return (stackTop == NULL);
-}
-
-/* Clear stack */
-template <class Type>
-void stack<Type>::clear() {
-    stackTop = NULL;
-}
-
-/* Add new item to the stack */
-template <class Type>
-void stack<Type>::push(Type item) {
-    node<Type> *newNode;
-    newNode = new node<Type>;
-    newNode->data = item;
-    newNode->next = stackTop;
-    stackTop = newNode;
-    size++;
-}
-
-/* Return the top element of the stack */
-template <class Type>
-Type stack<Type>::top() {
-    assert(stackTop != NULL);
-    return stackTop->data;
-}
-
-/* Remove the top element of the stack */
-template <class Type>
-void stack<Type>::pop() {
-    node<Type> *temp;
-    if (!isEmptyStack()) {
-        temp = stackTop;
-        stackTop = stackTop->next;
-        delete temp;
-        size--;
-    } else {
-        std::cout << "Stack is empty !" << std::endl;
-    }
-}
-
-/* Operator "=" */
-template <class Type>
-stack<Type> &stack<Type>::operator=(const stack<Type> &otherStack) {
-    node<Type> *newNode, *current, *last;
-
-    /* If stack is no empty, make it empty */
-    if (stackTop != NULL) {
-        stackTop = NULL;
-    }
-    if (otherStack.stackTop == NULL) {
-        stackTop = NULL;
-    } else {
-        current = otherStack.stackTop;
-        stackTop = new node<Type>;
-        stackTop->data = current->data;
-        stackTop->next = NULL;
-        last = stackTop;
-        current = current->next;
-        /* Copy the remaining stack */
-        while (current != NULL) {
-            newNode = new node<Type>;
-            newNode->data = current->data;
-            newNode->next = NULL;
-            last->next = newNode;
-            last = newNode;
-            current = current->next;
-        }
-    }
-    size = otherStack.size;
-    return *this;
-}
-
-#include <string>
-/** force instantiate to export the type class */
-template class stack<std::string>;
-template class stack<int>;
diff --git a/data_structures/stk/stack.h b/data_structures/stk/stack.h
deleted file mode 100644
index e038440a1..000000000
--- a/data_structures/stk/stack.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/* This class specifies the basic operation on a stack as a linked list */
-#ifndef DATA_STRUCTURES_STK_STACK_H_
-#define DATA_STRUCTURES_STK_STACK_H_
-
-/* Definition of the node */
-template <class Type>
-struct node {
-    Type data;
-    node<Type> *next;
-};
-
-/* Definition of the stack class */
-template <class Type>
-class stack {
- public:
-    void display();       /* Show stack */
-    stack();              /* Default constructor*/
-    ~stack();             /* Destructor */
-    bool isEmptyStack();  /* Determine whether the stack is empty */
-    void push(Type item); /* Add new item to the stack */
-    Type top();           /* Return the top element of the stack */
-    void pop();           /* Remove the top element of the stack */
-    void clear();
-
-    stack<Type> &operator=(const stack<Type> &otherStack);
-    // Overload "=" the assignment operator.
- private:
-    node<Type> *stackTop; /* Pointer to the stack */
-    int size;
-};
-
-#endif  // DATA_STRUCTURES_STK_STACK_H_
diff --git a/data_structures/stk/student.txt b/data_structures/student.txt
similarity index 100%
rename from data_structures/stk/student.txt
rename to data_structures/student.txt
diff --git a/data_structures/queue/test_queue.cpp b/data_structures/test_queue.cpp
similarity index 100%
rename from data_structures/queue/test_queue.cpp
rename to data_structures/test_queue.cpp
diff --git a/data_structures/stk/test_stack.cpp b/data_structures/test_stack.cpp
similarity index 100%
rename from data_structures/stk/test_stack.cpp
rename to data_structures/test_stack.cpp
diff --git a/data_structures/stk/main.cpp b/data_structures/test_stack_students.cpp
similarity index 100%
rename from data_structures/stk/main.cpp
rename to data_structures/test_stack_students.cpp