leetcode100 相同的树

思路与101完全相同

迭代：

class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(!p && !q) return true;
        queue<TreeNode*> que;
        que.push(p);
        que.push(q);
        while(!que.empty()){
            TreeNode* left = que.front();
            que.pop();
            TreeNode* right = que.front();
            que.pop();
            if(!left && !right) continue;
            if(!left || !right || left->val != right->val) return false;
            que.push(left->left);
            que.push(right->left);
            que.push(left->right);
            que.push(right->right);
        }
        return true;
    }
};

递归：

class Solution {
private:
    bool compare(TreeNode* p, TreeNode* q){
        if(!p && !q) return true;
        else if(!p && q) return false;
        else if(p && !q) return false;
        else if(p->val != q->val) return false;
        bool leftside = compare(p->left, q->left);
        bool rightside = compare(p->right, q->right);
        bool issame = leftside && rightside;
        return issame;
    }
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        bool res;
        res = compare(p, q);
        return res;
    }
};