hackoctoberfest2022

avl tree implement.cpp

@@ -0,0 +1,177 @@
+#include<stdio.h>
+#include<stdlib.h>
+struct Node
+{
+int key;
+struct Node *lft;
+struct Node *rgt;
+int height;
+};
+int max(int a, int b);
+int height(struct Node *N)
+{
+if (N == NULL)
+return 0;
+return N->height;
+}
+int max(int a, int b)
+{
+return (a > b)? a : b;
+}
+struct Node* newNode(int key)
+{
+struct Node* node = (struct Node*)
+malloc(sizeof(struct Node));
+node->key   = key;
+node->lft   = NULL;
+node->rgt  = NULL;
+node->height = 1;
+return(node);
+}
+struct Node *rgtRotate(struct Node *y)
+{
+struct Node *x = y->lft;
+struct Node *T2 = x->rgt;
+x->rgt = y;
+y->lft = T2;
+y->height = max(height(y->lft), height(y->rgt))+1;
+x->height = max(height(x->lft), height(x->rgt))+1;
+return x;
+}
+struct Node *lftRotate(struct Node *x)
+{
+struct Node *y = x->rgt;
+struct Node *T2 = y->lft;
+y->lft = x;
+x->rgt = T2;
+x->height = max(height(x->lft), height(x->rgt))+1;
+y->height = max(height(y->lft), height(y->rgt))+1;
+return y;
+}
+int getBalance(struct Node *N)
+{
+if (N == NULL)
+return 0;
+return height(N->lft) - height(N->rgt);
+}
+struct Node* insert(struct Node* node, int key)
+{
+if (node == NULL)
+return(newNode(key));
+if (key < node->key)
+node->lft  = insert(node->lft, key);
+else if (key > node->key)
+node->rgt = insert(node->rgt, key);
+else
+return node;
+node->height = 1 + max(height(node->lft),
+height(node->rgt));
+int balance = getBalance(node);
+if (balance > 1 && key < node->lft->key)
+return rgtRotate(node);
+if (balance < -1 && key > node->rgt->key)
+return lftRotate(node);
+if (balance > 1 && key > node->lft->key)
+{
+node->lft =  lftRotate(node->lft);
+return rgtRotate(node);
+}
+if (balance < -1 && key < node->rgt->key)
+{
+node->rgt = rgtRotate(node->rgt);
+return lftRotate(node);
+}
+return node;
+}
+struct Node * minValueNode(struct Node* node)
+{
+struct Node* current = node;
+/* loop down to find the lftmost leaf */
+while (current->lft != NULL)
+current = current->lft;
+return current;
+}
+struct Node* deleteNode(struct Node* base, int key)
+{
+if (base == NULL)
+return base;
+if ( key < base->key )
+base->lft = deleteNode(base->lft, key);
+else if( key > base->key )
+base->rgt = deleteNode(base->rgt, key);
+else
+{
+if( (base->lft == NULL) || (base->rgt == NULL) )
+{
+struct Node *temp = base->lft ? base->lft :
+base->rgt;
+if (temp == NULL)
+{
+temp = base;
+base = NULL;
+}
+else
+*base = *temp;
+free(temp);
+}
+else
+{
+struct Node* temp = minValueNode(base->rgt);
+base->key = temp->key;
+base->rgt = deleteNode(base->rgt, temp->key);
+}
+}
+if (base == NULL)
+return base;
+base->height = 1 + max(height(base->lft),
+height(base->rgt));
+int balance = getBalance(base);
+if (balance > 1 && getBalance(base->lft) >= 0)
+return rgtRotate(base);
+if (balance > 1 && getBalance(base->lft) < 0)
+{
+base->lft =  lftRotate(base->lft);
+return rgtRotate(base);
+}
+if (balance < -1 && getBalance(base->rgt) <= 0)
+return lftRotate(base);
+if (balance < -1 && getBalance(base->rgt) > 0)
+{
+base->rgt = rgtRotate(base->rgt);
+return lftRotate(base);
+}
+return base;
+}
+void preOrder(struct Node *base)
+{
+if(base != NULL)
+{
+printf("%d ", base->key);
+preOrder(base->lft);
+preOrder(base->rgt);
+}
+}
+int main()
+{
+struct Node *base = NULL;
+base = insert(base, 27);
+base = insert(base, 9);
+base = insert(base, 19);
+base = insert(base, 91);
+base = insert(base, 90);
+base = insert(base, 72);
+printf("The output of an AVL tree in preOrder form: \n");
+preOrder(base);
+printf("\n");
+base = deleteNode(base, 9);
+base = deleteNode(base, 72);
+printf("The tree in preOrder traversal outputs after deletion: \n");
+preOrder(base);
+printf("\n");
+base = insert(base, 1);
+base = insert(base, 2709);
+printf("The tree in preOrder traversal outputs 2 more inserts: \n");
+preOrder(base);
+printf("\n");
+return 0;
+}