leetcode 783

leetcode/783/783.go

@@ -0,0 +1,37 @@
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+
+var pre = -math.MaxInt32
+var res = math.MaxInt32
+
+func min(a, b int) int {
+    if a < b {
+        return a
+    }
+    return b
+}
+
+func dfs(root *TreeNode) {
+    if root == nil {
+        return
+    }
+    dfs(root.Left)
+    // fmt.Printf("(%d)%d ",pre, root.Val)
+    res = min(res, root.Val-pre)
+    pre = root.Val
+    dfs(root.Right)
+}
+
+func minDiffInBST(root *TreeNode) int {
+    pre = -math.MaxInt32
+    res = math.MaxInt32
+    dfs(root)
+    // fmt.Println()
+    return res
+}