树的子结构

/*struct TreeNode {    int val;    struct TreeNode *left;    struct TreeNode *right;    TreeNode(int x) :            val(x), left(NULL), right(NULL) {    }};*/class Solution {public:    bool HasSubtree(TreeNode* pRoot1, TreeNode* pRoot2)    {        bool bIsInclude = false;          //边界条件          if (NULL == pRoot1 || NULL == pRoot2)//表示结点为NULL，表示某条路径遍历结束，均不匹配。          {              return false;          }          //判断根节点          if (pRoot1->val == pRoot2->val)          {              bIsInclude =  IsInclude(pRoot1,pRoot2);          }          //判断左右子树是否匹配，但是在父亲已经匹配时，不用继续比较了          if (!bIsInclude)          {              bIsInclude =  HasSubtree(pRoot1->left, pRoot2);          }          if (!bIsInclude)          {              bIsInclude =  HasSubtree(pRoot1->right, pRoot2);          }          return bIsInclude;    }    bool IsInclude(TreeNode* pRootTarget,TreeNode* pRootPattern)      {          if (NULL == pRootPattern)//模式树为空，匹配成功          {              return true;          }          if (NULL == pRootTarget)//模式树不为空，主树为空，不匹配          {              return false;          }          if (pRootTarget->val != pRootPattern->val)          {              return false;          }          return IsInclude(pRootTarget->left,pRootPattern->left)               && IsInclude(pRootTarget->right,pRootPattern->right);       }};