Binary Tree Program in C

Trees/Binary_Trees/Binary Tree.c

@@ -0,0 +1,126 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+struct node
+{
+  int info;
+  struct node *left,*right;
+};
+
+typedef struct node* NODE;
+
+NODE getnode()
+{
+	NODE x;
+	// Allocate memory on heap for size of node structure
+	x= (NODE) malloc(sizeof(struct node));
+	// Display a message incase of allocation failure
+	if(x==NULL)printf("Node creation failure!\n");
+	// Return a pointer to the newly created node
+	return x;
+}
+
+NODE insert( int  item, NODE root)
+{
+  NODE temp, prev, cur;
+  char direction[10];
+  int i;
+  temp = getnode();
+  temp->info = item;
+  temp->right = NULL;
+  temp->left = NULL;
+  if(root == NULL) return temp;
+  printf("Enter the direction L for left and R for right:\n");
+  scanf("%s",direction);
+  for(i=0;direction[i]!='\0';i++)
+  direction[i] = toupper(direction[i]); //converts l->L and r->R for code simplicity 
+  prev = NULL;
+  cur = root;
+  for(i=0;direction[i]!='\0' && cur!=NULL; i++)
+  {
+    prev = cur;
+    if(direction[i]=='L')
+      cur = cur->left;
+    else
+      cur = cur->right;
+  }
+  if(cur!=NULL || i!=strlen(direction))
+  {
+    printf("Insert failure!");
+    free(temp);
+    return root;
+  }
+  if(direction[i-1]=='L')
+    prev->left = temp;
+  else if(direction[i-1]=='R')
+    prev->right = temp;
+  return root;
+}
+
+void in_order(NODE root)
+{
+  if(root == NULL)
+    return;
+  in_order(root->left);
+  printf("%d\t",root->info);
+  in_order(root->right);
+}
+
+void pre_order(NODE root)
+{
+  if(root == NULL)
+    return;
+  printf("%d\t",root->info);
+  pre_order(root->left);
+  pre_order(root->right);
+}
+void post_order(NODE root)
+{
+  if(root == NULL)
+    return;
+  post_order(root->left);
+  post_order(root->right);
+  printf("%d\t",root->info);
+}
+int main()
+{
+	NODE root = NULL;
+  int ch,data;
+	do
+	{
+		printf("\n1. Insert Element\n");
+		printf("2. In Order Traversal\n");
+		printf("3. Pre Order Traversal\n");
+    printf("4. Post Order Traversal\n");
+		printf("5. Exit\n");
+		printf("Enter your choice:");
+		scanf("%d",&ch);
+		switch(ch)
+		{
+			default:
+				break;
+			case 1:
+				printf("Enter element to insert:");
+				scanf("%d",&data);
+				root = insert(data,root);
+				break;
+			case 2:
+        printf("\nIn Order Traversal is:\n");
+				in_order(root);
+				break;
+			case 3:
+				printf("\nPre Order Traversal is:\n");
+        pre_order(root);
+				break;
+			case 4:
+			printf("\nPost Order Traversal is:\n");
+      post_order(root);
+			break;
+			case 5:
+				break;
+
+		}
+	}while(ch!=5);
+	return 0;
+}