题解 | #牛的奶量统计#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 *   public TreeNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param root TreeNode类 
     * @param targetSum int整型 
     * @return bool布尔型
     */
    public boolean hasPathSum (TreeNode root, int targetSum) {
        // write code here
        if(root == null){
            return false;
        }
        List<Integer> list = new ArrayList();
        sumArray(root,root.val,list);
        if(list.contains(targetSum)){
            return true;
        }else{
            return false;
        }
    }

    public void sumArray(TreeNode root,int sum,List<Integer> list){

        if(root.left == null && root.right == null){
            list.add(sum);
            return;
        }
        
        if(root.left != null){
            sumArray(root.left,sum + root.left.val,list);
        }
        
        if(root.right != null){
            sumArray(root.right,sum + root.right.val,list);
        }
    }
}