struct TreeNode {
int key;
TreeNode *left;
TreeNode *right;
};
bool isSubTree(TreeNode *A, TreeNode *B){
if(!A&&!B) return true;
if(!A||!B) return false;
if(A->key == B->key){
return isSubTree(A->left,B->left)&&isSubTree(A->right,B->right);
}else{
return isSubTree(A,B->left)||isSubTree(A,B->right)||isSubTree(A->left,B)||isSubTree(A->right,B);
}
}
递归,简洁,效率低下