add new solutions

solutions/5/q530/solution.go

@@ -0,0 +1,37 @@
+package q530
+
+import "math"
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func getMinimumDifference(root *TreeNode) int {
+	minDiff := math.MaxInt
+	var last *int
+
+	var check = func(num int) {
+		if last == nil {
+			last = &num
+			return
+		}
+		minDiff = min(minDiff, num-*last)
+		*last = num
+	}
+	var traverse func(node *TreeNode)
+	traverse = func(node *TreeNode) {
+		if node == nil {
+			return
+		}
+		traverse(node.Left)
+		check(node.Val)
+		traverse(node.Right)
+	}
+	traverse(root)
+
+	return minDiff
+}
+
+var _ = getMinimumDifference