Range Sum of BST
给一个BST和左边界/右边界. 求边界中的node的值的和.
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/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode() {} * TreeNode(int val) { this.val = val; } * TreeNode(int val, TreeNode left, TreeNode right) { * this.val = val; * this.left = left; * this.right = right; * } * } */ class Solution { public int rangeSumBST(TreeNode root, int L, int R) { if(root == null) return 0; if(root.val < L) return rangeSumBST(root.right, L, R); if(root.val > R) return rangeSumBST(root.left, L, R); return rangeSumBST(root.left, L, R) + rangeSumBST(root.right, L, R) + root.val; } } |