111. Minimum Depth of Binary Tree-LeetCode

// Just Use Traversing By Recursively 

class Solution {
public:
    int ans=INT_MAX;
    void max(TreeNode* root,int lev)
    {
         if(root->left==NULL&&root->right==NULL)
        {
             if(lev<ans)
             {
                 ans=lev;
             }
        }
        if(root->left!=NULL)
        {
            max(root->left,lev+1);
        }
        if(root->right!=NULL)
        {
            max(root->right,lev+1);
        }
}
    int minDepth(TreeNode* root) {
        if(root==NULL)
        {
            return 0;
        }
        max(root,0);
        return ans+1;
    }
};