Is SubTree
检查T2是否是T1的子树。
public class Subtree {
public int isSubTree(TreeNode T1, TreeNode T2) {
if (T2 == null) return 1;
if (T1 == null) return -1;
return (isSameTree(T1,T2) || isSubTree(T1.left, T2) == 1 || isSubTree(T1.right, T2) == 1);
}
public boolean isSameTree(TreeNode T1, TreeNode T2) {
if (T1 == null && T2 == null)
return true;
if (T1 == null || T2 == null)
return false;
if (T1.val != T2.val)
return false;
return (isSameTree(T1.left, T2.left) && isSameTree(T1.right, T2.right));
}
}