530. Minimum Absolute Difference in BST

README.md

@@ -1046,6 +1046,11 @@ Code: [`C#`](/src/csharp/Problems/FindSubsequences.cs)
 Tags: `Math` `Dynamic Programming` `Recursion` `Memoization`  
 Code: [`C#`](/src/csharp/Problems/Fibonacci.cs)  
 
+### [530. Minimum Absolute Difference in BST](https://leetcode.com/problems/minimum-absolute-difference-in-bst)
+
+Tags: `Tree` `Depth-First Search` `Breadth-First Search` `Binary Search Tree` `Binary Tree`  
+Code: [`C#`](/src/csharp/Problems/GetMinimumDifference.cs) [`Go`](/src/go/problems/get_minimum_difference_test.go) [`Python`](/src/python/problems/get_minimum_difference_test.py)  
+
 ### [542. 01 Matrix](https://leetcode.com/problems/01-matrix/)
 
 Tags: `Array` `Dynamic Programming` `Breadth-First Search` `Matrix`  

src/csharp/Problems/GetMinimumDifference.cs

@@ -0,0 +1,46 @@
+//https://leetcode.com/problems/binary-tree-inorder-traversal/
+
+namespace LeetCode.Problems;
+
+public sealed class GetMinimumDifference : ProblemBase
+{
+    [Theory]
+    [ClassData(typeof(GetMinimumDifference))]
+    public override void Test(object[] data) => base.Test(data);
+
+    protected override void AddTestCases()
+        => Add(it => it.ParamTree("[4,2,6,1,3]").Result(1))
+          .Add(it => it.ParamTree("[1,0,48,null,null,12,49]").Result(1))
+          .Add(it => it.ParamTree("[10,0,48,null,null,16,56]").Result(6));
+
+    private int Solution(TreeNode? root)
+    {
+        var stack = new Stack<TreeNode>();
+        TreeNode? prevNode = null;
+        var diff = int.MaxValue;
+
+        var node = root;
+        while (node != null || stack.Any())
+        {
+            if (node != null)
+            {
+                stack.Push(node);
+                node = node.left;
+            }
+            else
+            {
+                var pop = stack.Pop();
+                if (prevNode != null)
+                {
+                    diff = Math.Min(diff, pop.val - prevNode.val);
+                }
+
+                prevNode = pop;
+
+                node = pop.right;
+            }
+        }
+
+        return diff;
+    }
+}

src/go/problems/get_minimum_difference_test.go

@@ -0,0 +1,53 @@
+// https://leetcode.com/problems/minimum-absolute-difference-in-bst
+
+package problems
+
+import (
+	"math"
+	"testing"
+
+	"github.com/dobermanch/leetcode/core"
+)
+
+type GetMinimumDifference struct{}
+
+func TestGetMinimumDifference(t *testing.T) {
+	gen := core.TestSuite[GetMinimumDifference]{}
+	gen.Add(func(tc *core.TestCase) {
+		root := &TreeNode{
+			Val:   10,
+			Left:  &TreeNode{Val: 0, Left: &TreeNode{Val: 4}},
+			Right: &TreeNode{Val: 48, Left: &TreeNode{Val: 16}, Right: &TreeNode{Val: 56}},
+		}
+		tc.Param(root).Result(6)
+	}).Run(t)
+}
+
+func (GetMinimumDifference) Solution(root *TreeNode) int {
+	stack := []*TreeNode{}
+	diff := math.MaxInt
+
+	node := root
+	var prevNode *TreeNode
+	for node != nil || len(stack) > 0 {
+		if node != nil {
+			stack = append(stack, node)
+			node = node.Left
+		} else {
+			pop := stack[len(stack)-1]
+			stack = stack[:len(stack)-1]
+
+			if prevNode != nil {
+				newDiff := pop.Val - prevNode.Val
+				if newDiff < diff {
+					diff = newDiff
+				}
+			}
+
+			prevNode = pop
+			node = pop.Right
+		}
+	}
+
+	return diff
+}

src/python/problems/get_minimum_difference_test.py

@@ -0,0 +1,34 @@
+# https://leetcode.com/problems/minimum-absolute-difference-in-bst
+
+from typing import Optional
+from core.problem_base import *
+from models.tree_node import TreeNode
+
+class GetMinimumDifference(ProblemBase):
+    def Solution(self, root: Optional[TreeNode]) -> int:
+        stack = []
+        diff = 10**5
+
+        node = root
+        prevNode = None
+        while node or len(stack) > 0:
+            if node:
+                stack.append(node)
+                node = node.left
+            else:
+                pop = stack.pop()
+
+                if prevNode:
+                    diff = min(diff, pop.val - prevNode.val)
+
+                prevNode = pop
+                node = pop.right
+
+        return diff
+
+if __name__ == '__main__':
+    TestGen(GetMinimumDifference) \
+        .Add(lambda tc: tc.ParamTreeNode([4,2,6,1,3]).Result(1)) \
+        .Add(lambda tc: tc.ParamTreeNode([1,0,48,None,None,12,49]).Result(1)) \
+        .Add(lambda tc: tc.ParamTreeNode([10,0,48,None,None,16,56]).Result(6)) \
+        .Run()