Merge pull request #475 from openset/develop

Add: Sum of Root To Leaf Binary Numbers

Author: Shuo

problems/sum-of-root-to-leaf-binary-numbers/sum_of_root_to_leaf_binary_numbers.go

@@ -0,0 +1,27 @@
+package sum_of_root_to_leaf_binary_numbers
+
+import . "github.com/openset/leetcode/internal/kit"
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func sumRootToLeaf(root *TreeNode) int {
+	if root.Left == nil && root.Right == nil {
+		return root.Val
+	}
+	sum := 0
+	if root.Left != nil {
+		root.Left.Val += root.Val << 1
+		sum += sumRootToLeaf(root.Left)
+	}
+	if root.Right != nil {
+		root.Right.Val += root.Val << 1
+		sum += sumRootToLeaf(root.Right)
+	}
+	return sum
+}

problems/sum-of-root-to-leaf-binary-numbers/sum_of_root_to_leaf_binary_numbers_test.go

@@ -0,0 +1,35 @@
+package sum_of_root_to_leaf_binary_numbers
+
+import (
+	"testing"
+
+	. "github.com/openset/leetcode/internal/kit"
+)
+
+type caseType struct {
+	input    []int
+	expected int
+}
+
+func TestSumRootToLeaf(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{1, 0, 1, 0, 1, 0, 1},
+			expected: 22,
+		},
+		{
+			input:    []int{1, 1},
+			expected: 3,
+		},
+		{
+			input:    []int{1, NULL, 0},
+			expected: 2,
+		},
+	}
+	for _, tc := range tests {
+		output := sumRootToLeaf(SliceInt2TreeNode(tc.input))
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}