剑指offer面试题18：二叉树的子结构

struct BinaryTreeNode
{
int value;
BinaryTreeNode *left,*right;
};
bool doestree1havetree2(BinaryTreeNode *root1,BinaryTreeNode *root2);
bool hassubtree(BinaryTreeNode *root1,BinaryTreeNode *root2)
{
bool result=false;
if(root1!=NULL&&root2!=NULL)
{
if(root1->value==root2->value)
{
result=doestree1havetree2(root1,root2);
}
if(!result)result=hassubtree(root1->left,root2);
if(!result)result=hassubtree(root1->right,root2);
}
return result;
}
bool doestree1havetree2(BinaryTreeNode *root1,BinaryTreeNode *root2)
{
if(root2==NULL)
return true;
if(root1==NULL)
return false;
if(root1->value!=root2->value)
return false;
return doestree1havetree2(root1->left,root2->left)&&doestree1havetree2(root1->right,root2->right);
}