added problem 2265

Author: SHA65536

problems/problem2265/get_avg_nodes.go

@@ -0,0 +1,31 @@
+package problem2265
+
+import . "leetcodedaily/helpers/binarytree"
+
+/*
+Given the root of a binary tree, return the number of nodes where the value of the node is equal to the average of the values in its subtree.
+Note:
+The average of n elements is the sum of the n elements divided by n and rounded down to the nearest integer.
+A subtree of root is a tree consisting of root and all of its descendants.
+*/
+
+func averageOfSubtree(root *TreeNode) int {
+	var res int
+	var dfs func(*TreeNode) (int, int)
+
+	dfs = func(cur *TreeNode) (int, int) {
+		if cur == nil {
+			return 0, 0
+		}
+		lS, lC := dfs(cur.Left)
+		rS, rC := dfs(cur.Right)
+		if cur.Val == (lS+rS+cur.Val)/(lC+rC+1) {
+			res++
+		}
+		return (lS + rS + cur.Val), (lC + rC + 1)
+	}
+
+	dfs(root)
+
+	return res
+}

problems/problem2265/get_avg_nodes_test.go

@@ -0,0 +1,38 @@
+package problem2265
+
+import (
+	"fmt"
+	"testing"
+
+	. "leetcodedaily/helpers/binarytree"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type TestCase struct {
+	Input    *TreeNode
+	Expected int
+}
+
+var TestCases = []TestCase{
+	{MakeTree(4, 8, 0, NULL, NULL, 1, NULL, NULL, 5, NULL, 6, NULL, NULL), 5},
+	{MakeTree(1, NULL, NULL), 1},
+}
+
+func TestTreeNodeAvg(t *testing.T) {
+	assert := assert.New(t)
+
+	for _, tc := range TestCases {
+		want := tc.Expected
+		got := averageOfSubtree(tc.Input)
+		assert.Equal(want, got, fmt.Sprintf("%+v", tc))
+	}
+}
+
+func BenchmarkTreeNodeAvg(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, tc := range TestCases {
+			averageOfSubtree(tc.Input)
+		}
+	}
+}

readme.md

@@ -555,6 +555,7 @@ Each problem is in it's own directory, with test files. There are helper package
 | 2246 | [Longest Path With Different Adjacent Characters](https://leetcode.com/problems/longest-path-with-different-adjacent-characters) | [My Solution](./problems/problem0000) | ✅ |
 | 2256 | [Minimum Average Difference](https://leetcode.com/problems/minimum-average-difference/) | [My Solution](./problems/problem2256) | ✅ |
 | 2259 | [Remove Digit From Number to Maximize Result](https://leetcode.com/problems/remove-digit-from-number-to-maximize-result) | [My Solution](./problems/problem2259) | ✅ |
+| 2265 | [Count Nodes Equal to Average of Subtree](https://leetcode.com/problems/count-nodes-equal-to-average-of-subtree) | [My Solution](./problems/problem2265) | ✅ |
 | 2272 | [Substring With Largest Variance](https://leetcode.com/problems/substring-with-largest-variance) | [My Solution](./problems/problem2272) | ✅ |
 | 2278 | [Percentage of Letter in String](https://leetcode.com/problems/percentage-of-letter-in-string) | [My Solution](./problems/problem2278) | ✅ |
 | 2279 | [Maximum Bags With Full Capacity of Rocks](https://leetcode.com/problems/maximum-bags-with-full-capacity-of-rocks) | [My Solution](./problems/problem2279) | ✅ |