Add: Range Sum of BST

problems/range-sum-of-bst/range_sum_of_bst.go

@@ -1 +1,25 @@
 package range_sum_of_bst
+
+import . "github.com/openset/leetcode/internal/kit"
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func rangeSumBST(root *TreeNode, L int, R int) int {
+	ans := 0
+	if root.Val >= L && root.Val <= R {
+		ans += root.Val
+	}
+	if root.Left != nil && root.Val > L {
+		ans += rangeSumBST(root.Left, L, R)
+	}
+	if root.Right != nil && root.Val < R {
+		ans += rangeSumBST(root.Right, L, R)
+	}
+	return ans
+}

problems/range-sum-of-bst/range_sum_of_bst_test.go

@@ -1 +1,37 @@
 package range_sum_of_bst
+
+import (
+	"testing"
+
+	. "github.com/openset/leetcode/internal/kit"
+)
+
+type caseType struct {
+	input    []int
+	l        int
+	r        int
+	expected int
+}
+
+func TestRangeSumBST(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{10, 5, 15, 3, 7, NULL, 18},
+			l:        7,
+			r:        15,
+			expected: 32,
+		},
+		{
+			input:    []int{10, 5, 15, 3, 7, 13, 18, 1, NULL, 6},
+			l:        6,
+			r:        10,
+			expected: 23,
+		},
+	}
+	for _, tc := range tests {
+		output := rangeSumBST(SliceInt2TreeNode(tc.input), tc.l, tc.r)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}