Leetcode::SameTree

同时遍历两个树；

 1 /**
 2 * Definition for binary tree
 3 * struct TreeNode {
 4 * int val;
 5 * TreeNode *left;
 6 * TreeNode *right;
 7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8 * };
 9 */
10 class Solution {
11 public:
12 bool isSameTree(TreeNode *p, TreeNode *q) {
13 // Start typing your C/C++ solution below
14 // DO NOT write int main() function
15 stack<TreeNode *> s_p,s_q;
16 
17 
18 if( !p && ! q)
19 {
20     return true;
21 }
22 else if ( p && q )
23 {
24 
25     while( (p && q ) ||( !s_p.empty()&& ! s_q.empty() ))
26     {
27         if( p && q)
28         {
29             if(p->val != q->val)
30             {
31                 return false;
32             }
33 
34             s_p.push(p);
35             s_q.push(q);
36             p=p->left;
37             q=q->left;
38         }
39         else if( !p && !q)
40         {
41             p=s_p.top();
42             q=s_q.top();
43             s_p.pop();
44             s_q.pop();
45             p=p->right;
46             q=q->right;
47         }
48         else
49         {
50             return false;
51         }
52     }
53 
54     return true;
55 }
56 else
57 {
58     return false;
59 }
60 
61 }
62 };
63 
64

 

递归实现：

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     bool isSameTree(TreeNode *p, TreeNode *q) {
13         // Start typing your C/C++ solution below
14         // DO NOT write int main() function
15        if( p == NULL && q == NULL )
16        {
17            return true;
18        }
19        
20        if( p && q )
21        {
22            if( p->val == q->val )
23            {
24                return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);
25            }
26        }
27        
28        return false;
29     }
30 };

 

posted @ 2013-05-30 17:18  NinaGood  阅读(136)  评论(0)    收藏  举报