AVL Tree algorithm is added in C

avl_tree.c

@@ -0,0 +1,214 @@
+#include<stdio.h>
+#include<stdlib.h>
+
+typedef struct Node{
+    int data;
+    struct Node* left;
+    struct Node* right;
+    int height;
+} node;
+
+int max(int a , int b){
+    return (a > b)? a:b;
+}
+
+node* getNode(int val){
+    node* temp = (node *)malloc(sizeof(node));
+
+    temp->data = val;
+    temp->left = NULL;
+    temp->right = NULL;
+    temp->height = 1;
+
+    return temp;
+}
+
+int getHeight(node* root){
+    if(root == NULL){
+        return 0;
+    }
+
+    return root->height;
+}
+
+node* rotateRight(node* root){
+    if(root == NULL) return root;
+
+    node* t1 = root->left;
+    node* t2 = t1->right;
+
+    t1->right = root;
+    root->left = t2;
+
+    root->height = 1 + max(getHeight(root->left),getHeight(root->right));
+    t1->height = 1 + max(getHeight(t1->left),getHeight(t1->right));
+
+    return t1;
+}
+
+node* rotateLeft(node* root){
+    if(root == NULL) return root;
+
+    node* t1 = root->right;
+    node* t2 = t1->left;
+
+    t1->left = root;
+    root->right = t2;
+
+    root->height = 1 + max(getHeight(root->left),getHeight(root->right));
+    t1->height = 1 + max(getHeight(t1->left),getHeight(t1->right));
+
+    return t1;
+}
+
+int balanceFactor(node* root){
+    if(root == NULL) return 0;
+
+    return (getHeight(root->left) - getHeight(root->right));
+}
+
+node* insertNode(node* root , int val){
+
+    node* n = getNode(val);
+
+    if(root == NULL)    return n;
+
+    if(val > root->data){
+        root->right = insertNode(root->right,val);
+    }
+    else{
+        root->left = insertNode(root->left,val);
+    }
+
+    root->height = 1 + max(getHeight(root->left),getHeight(root->right));
+
+    int bal = balanceFactor(root);
+
+    if(bal > 1 && val < root->left->data){
+        return rotateRight(root);
+    }
+
+    if(bal > 1 && val > root->left->data){
+        root->left = rotateLeft(root->left);
+        return rotateRight(root);
+    }
+
+    if(bal < -1 && val > root->right->data){
+        return rotateLeft(root);
+    }
+
+    if(bal < -1 && val < root->right->data){
+        root->right = rotateRight(root->right);
+        return rotateLeft(root);
+    }
+
+    return root;
+}
+
+
+node* inorderSucc(node* root){
+
+    node* temp = root;
+
+    while(temp->left != NULL){
+        temp = temp->left;
+    }
+
+    return temp;
+}
+
+node* deleteNode(node* root , int val){
+    if(root == NULL) return root;
+
+    if(val > root->data){
+        root->right = deleteNode(root->right,val);
+    }
+    else if(val < root->data){
+        root->left = deleteNode(root->left,val);
+    }
+    else{
+
+        node* t;
+
+        if(root->left == NULL){
+
+            t = root->right;
+            free(root);
+            return t;
+        }
+        else if(root->right == NULL){
+
+            t = root->left;
+            free(root);
+            return t;
+        }
+        else{
+            node* temp = inorderSucc(root->right);
+
+            root->data = temp->data;
+            root->right = deleteNode(root->right,temp->data);
+        }
+
+        if(root == NULL){
+            return root;
+        }
+
+        root->height = 1  + max(getHeight(root->left),getHeight(root->right));
+
+        int bal = balanceFactor(root);
+
+        if(bal > 1 && balanceFactor(root->left) >= 0){
+            return rotateRight(root);
+        }
+
+        if(bal > 1 && balanceFactor(root->right) < 0){
+            root->left = rotateLeft(root->left);
+
+            return rotateRight(root->right);
+        }
+
+        if(bal < -1 && balanceFactor(root->right) <= 0){
+            return rotateLeft(root);
+        }
+
+        if(bal < -1 && balanceFactor(root->right) > 0){
+            root->right = rotateRight(root->right);
+            return rotateLeft(root);
+        }
+    }
+
+    return root;
+}
+
+void inorder(node* root){
+    if(root == NULL)    return;
+
+    inorder(root->left);
+    printf("%d ",root->data);
+    inorder(root->right);
+}
+
+int main(){
+
+    node* root = NULL;
+
+    root = insertNode(root,1);
+    root = insertNode(root,2);
+    root = insertNode(root,3);
+    root = insertNode(root,4);
+    root = insertNode(root,5);
+    root = insertNode(root,6);
+    root = insertNode(root,7);
+
+    inorder(root);
+    puts("");
+
+    root = deleteNode(root,4);
+    root = deleteNode(root,1);
+    root = deleteNode(root,7);
+
+    inorder(root);
+    puts("");
+
+    return 0;
+}