剑指 Offer 26. 树的子结构
思路
1.当树A为空或树B为空时,直接返回 false ;
2.比较当前两个节点为根节点是否一致
3.比较A节点的左右子树与B是否一致
代码
public boolean isSubStructure(TreeNode A, TreeNode B) {
return (A!=null&&B!=null)&&(helper(A,B)||isSubStructure(A.left,B)||isSubStructure(A.right,B));
}
public boolean helper(TreeNode A,TreeNode B){
if(B==null)return true;
if(A==null||A.val!=B.val)return false;
return helper(A.left,B.left)&&helper(A.right,B.right);
}