leetcode-111. Minimum Depth of Binary Tree

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to >the nearest leaf node.

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思路：递归

/**
* Definition for a binary tree node.
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
int minLength = 1;
bool stopFlag = false;
public:
int minDepth(TreeNode* root) {
if(root == NULL)
{
return 0;
}
int leftDep = minDepth(root->left);
int rightDep = minDepth(root->right);

return (leftDep == 0 || rightDep == 0)?(leftDep+rightDep+1):min(leftDep,rightDep)+1;
}

};