add new solutions

solutions/11/q1161/solution.go

@@ -0,0 +1,43 @@
+package q1161
+
+import "math"
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func maxLevelSum(root *TreeNode) int {
+	type qElem struct {
+		node  *TreeNode
+		level int
+	}
+	queue := make([]qElem, 0, 256)
+	queue = append(queue, qElem{root, 1})
+
+	maxSum, maxLvl := math.MinInt, 0
+	sum, lvl := 0, 1
+	for ; len(queue) > 0; queue = queue[1:] {
+		cur := &queue[0]
+		if cur.level != lvl {
+			if sum > maxSum {
+				maxSum, maxLvl = sum, lvl
+			}
+			sum, lvl = 0, cur.level
+		}
+		sum += cur.node.Val
+		if cur.node.Left != nil {
+			queue = append(queue, qElem{cur.node.Left, cur.level + 1})
+		}
+		if cur.node.Right != nil {
+			queue = append(queue, qElem{cur.node.Right, cur.level + 1})
+		}
+	}
+	if sum > maxSum {
+		return lvl
+	}
+	return maxLvl
+}
+
+var _ = maxLevelSum