Create problem24

Author: rmkcodingclub

problem24

@@ -0,0 +1,65 @@
+//Solution by Pavithra B, 111712205071, IT dept.
+
+/* c code to find closest anchestor of two nodes */
+#include <stdio.h>
+#include <stdlib.h>
+ 
+struct node
+{
+    int data;
+    struct node* left, *right;
+};
+ 
+/* Function to find LCA of n1 and n2. The function assumes that both
+   n1 and n2 are present in BST */
+struct node *lca(struct node* root, int n1, int n2)
+{
+    if (root == NULL) return NULL;
+ 
+    // If both n1 and n2 are smaller than root, then LCA lies in left
+    if (root->data > n1 && root->data > n2)
+        return lca(root->left, n1, n2);
+ 
+    // If both n1 and n2 are greater than root, then LCA lies in right
+    if (root->data < n1 && root->data < n2)
+        return lca(root->right, n1, n2);
+ 
+    return root;
+}
+ 
+/*  function that allocates a new node with the given data.*/
+struct node* newNode(int data)
+{
+    struct node* node = (struct node*)malloc(sizeof(struct node));
+    node->data  = data;
+    node->left  = node->right = NULL;
+    return(node);
+}
+ 
+/* code to test */
+int main()
+{
+    // Let us construct the BST shown in the above figure
+    struct node *root        = newNode(20);
+    root->left               = newNode(8);
+    root->right              = newNode(22);
+    root->left->left         = newNode(4);
+    root->left->right        = newNode(12);
+    root->left->right->left  = newNode(10);
+    root->left->right->right = newNode(14);
+ 
+    int n1 = 10, n2 = 14;
+    struct node *t = lca(root, n1, n2);
+    printf("LCA of %d and %d is %d \n", n1, n2, t->data);
+ 
+    n1 = 14, n2 = 8;
+    t = lca(root, n1, n2);
+    printf("LCA of %d and %d is %d \n", n1, n2, t->data);
+ 
+    n1 = 10, n2 = 22;
+    t = lca(root, n1, n2);
+    printf("LCA of %d and %d is %d \n", n1, n2, t->data);
+ 
+    getchar();
+    return 0;
+}