Find right most and left most node of BST

binary_search_tree.c

@@ -71,6 +71,93 @@ void add_value_to_tree(NODE ** addr_of_root, int character) {
     }
 }
 
+// Function to know if node is right most node or not
+// Return 1 if node is right most node
+// Return 0 otherwise
+int is_right_most_node(NODE * node) {
+    // Keep going up following right-child
+    // if we can reach the root, then node is right most node
+    // if we cannot reach the root, it is not the right most node
+
+    // return 0 if node is null
+    if (node == NULL) 
+        return 0;
+
+    // return 0 if right child of node is not null
+    if ((*node).right != NULL)
+        return 0;
+
+
+    while(1) {
+        NODE * parent = (*node).parent;
+        if (parent == NULL) {
+            // we have reached the root
+            return 1;
+        }
+        if ((*parent).right == node)
+            node = (*node).parent;
+        // if node is not right child then it is left child,
+        // and therefore it cannot be right most node
+        else
+            return 0;
+    }
+}
+
+// Function to get right most node
+// In binary search tree, right most node is
+// same as max value in the tree
+NODE * get_right_most_node(NODE * root) {
+    // return if root is null
+    if (root == NULL) {
+        return NULL;
+    }
+
+    // create a temp node. initialize it with root
+    // keep on traversing temp.right until temp.right is null
+    // you will reach right most node
+    NODE * temp = root;
+    while((*temp).right != NULL) {
+        temp = (*temp).right;
+    }
+    return temp;
+}
+
+// Function to get left most node
+// In binary search tree, left most node is
+// same as min value in the tree
+NODE * get_left_most_node(NODE * root) {
+    // return if root is null
+    if (root == NULL) {
+        return NULL;
+    }
+
+    // create a temp node. initialize it with root
+    // keep on traversing temp.left until temp.left is null
+    // you will reach left most node
+    NODE * temp = root;
+    while((*temp).left != NULL) {
+        temp = (*temp).left;
+    }
+    return temp;
+}
+
+void print_tree_increasing_order (NODE * root) {
+    if (root == NULL)
+        return;
+
+    // print all values on left subtree
+    print_tree_increasing_order((*root).left);
+
+    // print root
+    if (is_right_most_node(root) == 1)
+        printf("%d", (*root).value);
+    else
+        printf("%d, ", (*root).value);
+
+    // print all values on right subtree
+    print_tree_increasing_order((*root).right);
+}
+
 // Inorder traverdal of tree
 void print_in_order (NODE * node) {
     // In order traversal - Left Root Right
@@ -91,12 +178,17 @@ void print_in_order (NODE * node) {
 int main(void) {
     NODE * root = NULL;
 
+    // stdin: 1 10 3 2 20 30 4 18 11
+
     int character;
     while((scanf("%d", &character)) != EOF) {
         // add value to tree
         add_value_to_tree(&root, character);
+        // printf("%d\n", (*root).value);
     }
     print_in_order(root);
+    printf("\n");
+    print_tree_increasing_order(root);
 
     return 0;
 }