Q4_8.java

public class Q4_8{
	public static void main(String[] args){
		int[] array = { 1,2,3,4,5,6,7,8 };
		int[] subArray  ={5,6,7,8};
		TreeNode<Integer> root1 = new Q4_3().arrayToBST(array, 0, 7);
		TreeNode<Integer> root2 = new Q4_3().arrayToBST(subArray, 0, 3);
		/*TreeNode<Integer> root2 = new TreeNode<Integer>(7,null,new TreeNode<Integer>(8));*/
		System.out.println(isSubTree(root1,root2));
	}
	public static boolean isSubTree(TreeNode<Integer> root1, TreeNode<Integer> root2){
		if(root1==null)
			return false;
		if(root2==null)
			return true;
		TreeNode<Integer> cur = root1;
		if(cur.value == root2.value)
			if(match(cur,root2))
				return true;
		if(isSubTree(root1.left,root2))
			return true;
		if(isSubTree(root1.right,root2))
			return true;
		return false;
	}
	public static boolean match(TreeNode<Integer> node1, TreeNode<Integer> node2){
		if(node1 == null && node2 ==null)
			return true;
		if(node1==null || node2== null)
			return false;
		if(node1.value == node2.value)
			return match(node1.left,node2.left) && match(node1.right, node2.right);
		else return false;
	}
}