Modified Median.c and BinarySearch.c. Added data_structures directory with stack implementation

Computer Oriented Statistical Methods/MEDIAN.C

@@ -1,6 +1,7 @@
 #include<stdio.h>
-#include<conio.h>
+//#include<conio.h>
 #include<math.h>
+
 void main()
 {
 	int a[10],n,i,j,temp;
@@ -46,4 +47,4 @@ void main()
 	}
 	printf("\nMedian is : %f",median);
 	getch();
-}
+}

data_structures/stack.c

@@ -0,0 +1,135 @@
+/**
+ * Kyler Smith, 2017
+ * Stack data structure implementation.
+ */
+
+////////////////////////////////////////////////////////////////////////////////
+//INCLUDES
+#include <stdio.h>
+#include <stdlib.h>
+
+////////////////////////////////////////////////////////////////////////////////
+//MACROS: CONSTANTS
+
+////////////////////////////////////////////////////////////////////////////////
+//DATA STRUCTURES
+struct node {
+    int data;
+    struct node* next;
+    struct node* pre;
+} *head, *tmp;
+
+////////////////////////////////////////////////////////////////////////////////
+//GLOBAL VARIABLES
+int count = 0;
+
+////////////////////////////////////////////////////////////////////////////////
+//FUNCTION PROTOTYPES
+void create();
+void push(int x);
+int pop();
+int peek();
+int size();
+int isEmpty();
+
+////////////////////////////////////////////////////////////////////////////////
+//MAIN ENTRY POINT
+
+int main(int argc, char const *argv[]) {
+
+    int x, y, z;
+
+    create();
+    push(4);
+    x = pop();
+    // 4. Count: 0. Empty: 1.
+    printf("%d.\t\tCount: %d.\tEmpty: %d.\n", x, size(), isEmpty());
+
+    push(1);
+    push(2);
+    push(3);
+    x = pop();
+    y = pop();
+    // 3, 2. Count: 1. Empty: 0;
+    printf("%d, %d.\t\tCount: %d.\tEmpty: %d.\n", x, y, size(), isEmpty());
+    pop();  // Empty the stack.
+
+    push(5);
+    push(6);
+    x = peek();
+    push(7);
+    y = pop();
+    push(8);
+    z = pop();
+    // 1, 6, 7, 8. Count: 2. Empty: 0.
+    printf("%d, %d, %d.\tCount: %d.\tEmpty: %d.\n", x, y, z, size(), isEmpty());
+
+	return 0;
+}
+
+/**
+ * Initialize the stack to NULL.
+ */
+void create() {
+    head = NULL;
+}
+
+/**
+ * Push data onto the stack.
+ */
+void push(int x) {
+    if(head == NULL) {
+        head = (struct node *)malloc(1 * sizeof(struct node));
+        head->next = NULL;
+        head->pre = NULL;
+        head->data = x;
+    } else {
+        tmp = (struct node *)malloc(1 * sizeof(struct node));
+        tmp->data = x;
+        tmp->next = NULL;
+        tmp->pre = head;
+        head = tmp;
+    }
+    ++count;
+}
+
+/**
+ * Pop data from the stack
+ */
+int pop() {
+    int returnData;
+    if(head == NULL) {
+        printf("ERROR: Pop from empty stack.\n");
+        exit(1);
+    } else {
+        returnData = head->data;
+
+        if(head->pre == NULL)
+            head = NULL;
+        else {
+            head = head->pre;
+            free(head->next);
+        }
+    }
+    --count;
+    return returnData;
+}
+
+int peek() {
+    if(head != NULL)
+        return head->data;
+    else {
+        printf("ERROR: Peeking from empty stack.");
+        exit(1);
+    }
+}
+
+int size() {
+    return count;
+}
+
+int isEmpty() {
+    if(count == 0)
+        return 1;
+    return 0;
+}

searching/BinarySearch.c

@@ -33,7 +33,7 @@ int main(void)
    // set result to what is returned from binarysearch
    int result = binarysearch(arr, 0, n-1, x);
    // print out result
-   (result == -1)? printf("Element is not in the array")
-                 : printf("Element is present at index %d", result);
+   (result == -1) ? printf("Element is not in the array\n")
+                 : printf("Element is present at index %d\n", result);
    return 0;
 }