树的子结构

白板硬刚就完事儿了

class Solution {
public:
    bool judge(TreeNode* pRoot1, TreeNode* pRoot2){
        if(pRoot2==NULL){
            return true;
        }if((pRoot1==NULL && pRoot2!=NULL) || pRoot1->val!=pRoot2->val){
            return false;
        }
        return judge(pRoot1->left,pRoot2->left)&&judge(pRoot1->right,pRoot2->right);
    }
    bool flag=false;
    void preOrder(TreeNode* pRoot1, TreeNode* pRoot2){
        if(pRoot1==NULL)return ;
        if(pRoot1->val==pRoot2->val){
            if(judge(pRoot1,pRoot2)){
                flag=true;
                return ;
            }
        }
        preOrder(pRoot1->left,pRoot2);
        if(flag)return ;
        preOrder(pRoot1->right,pRoot2);
    }
    bool HasSubtree(TreeNode* pRoot1, TreeNode* pRoot2){
        if(pRoot2==NULL)return false;
        preOrder(pRoot1,pRoot2);
        return flag;
    }
};