Minimum distance between two nodes

 public class MinimumDistanceBetweenTwoNodes {

    public static class Node {

        int data;

        Node left, right;

        Node(int data) {

            this.data = data;

            this.left = null;

            this.right = null;

        }

    }

    public static Node lca(Node root, int n1, int n2) {

        if (root == null || root.data == n1 | root.data == n2) {

            return root;

        }

        Node lefftsubtree = lca(root.left, n1, n2);

        Node rightsubttree = lca(root.right, n1, n2);

        if (lefftsubtree == null) {

            return rightsubttree;

        }

        if (rightsubttree == null) {

            return lefftsubtree;

        }

        return root;

    }

    public static int lcaDist(Node root, int n) {

        if (root == null) {

            return -1;

        }

        if (root.data == n) {

            return 0;

        }

        int leftDist = lcaDist(root.left, n);

        int rightDist = lcaDist(root.right, n);

        if (leftDist == -1 && rightDist == -1) {

            return -1;

        } else if (leftDist == -1) {

            return rightDist + 1;

        } else {

            return leftDist + 1;

        }

    }

    public static int MinDist(Node root, int n1, int n2) {

        Node lca = lca(root, n1, n2);

        int dist1 = lcaDist(lca, n1);

        int dist2 = lcaDist(lca, n2);

        return dist1 + dist2;

    }

    public static void main(String[] args) {

        Node root = new Node(1);

        root.left = new Node(2);

        root.right = new Node(3);

        root.left.left = new Node(4);

        root.left.right = new Node(5);

        root.right.left = new Node(6);

        root.right.right = new Node(7);

        System.out.println("the Minimum distance between n1 and n2: " + MinDist(root, 4, 7));

    }

}