Minimum depth of binary tree

---

题目内容

尝试一

result:答案正确:恭喜！您提交的程序通过了所有的测试用例
code:

/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    //mean the min depth
    private int minDepth;
    public int run(TreeNode root) {
        minDepth=Integer.MAX_VALUE;
        if(root==null){
            minDepth=0;
            return minDepth;
        }
        run(root,0);
        return minDepth;
    }
    
    /*now：the current depth */
    private void run(TreeNode root,int now){
    	/*another end mark of recursive function*/
        if(root==null){
            return ;
        }
        now++;
        run(root.left,now);
        run(root.right,now);
        /*warning:the end mark of recursive function is  root.left==null && root.right==null */
        if(root.left==null && root.right==null){
            if(now<minDepth){
                minDepth=now;
            }
            return;
        }
    }
}

分析：注意递归结束标识有root.left==null && root.right==null，此时才应该将最小depth存到minDepth。

结论

1. 求整数的最大值：Integer.MAX_VALUE;