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 void minDepth(TreeNode * node, int & minDep, int curDepth){
13 if (curDepth>=minDep)
14 return;
15 if (node==NULL)
16 return;
17 if (node->left==NULL && node->right==NULL){
18 minDep = curDepth;
19 }
20 if (node->left != NULL)
21 minDepth(node->left, minDep, curDepth+1);
22 if (node->right != NULL)
23 minDepth(node->right, minDep, curDepth+1);
24 }
25 int minDepth(TreeNode *root) {
26 // IMPORTANT: Please reset any member data you declared, as
27 // the same Solution instance will be reused for each test case.
28 if (root==NULL)
29 return 0;
30 const int maxNum = 1000000000;
31 int minDep = maxNum;
32 minDepth(root, minDep, 1);
33 return minDep;
34 }
35 };
