add sol

Author: ductnn

leetcode/topic/B-Tree/515/sol.go

@@ -0,0 +1,63 @@
+// https://leetcode.com/problems/find-largest-value-in-each-tree-row/
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+// TreeNode definition
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func largestValues(root *TreeNode) []int {
+	if root == nil {
+		return []int{}
+	}
+
+	res := []int{}
+	queue := []*TreeNode{root}
+
+	for len(queue) > 0 {
+		levelSize := len(queue)
+		maxVal := math.MinInt32
+
+		for i := 0; i < levelSize; i++ {
+			node := queue[0]
+			queue = queue[1:]
+
+			if node.Val > maxVal {
+				maxVal = node.Val
+			}
+
+			if node.Left != nil {
+				queue = append(queue, node.Left)
+			}
+			if node.Right != nil {
+				queue = append(queue, node.Right)
+			}
+		}
+		res = append(res, maxVal)
+	}
+
+	return res
+}
+
+func main() {
+	root := &TreeNode{
+		Val: 1,
+		Left: &TreeNode{
+			Val:   3,
+			Left:  &TreeNode{Val: 5},
+			Right: &TreeNode{Val: 3},
+		},
+		Right: &TreeNode{
+			Val:   2,
+			Right: &TreeNode{Val: 9},
+		},
+	}
+	fmt.Println(largestValues(root))
+}