111 ut pass

Author: aQua

Algorithms/0111.minimum-depth-of-binary-tree/README.md

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+# [111. Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/)
+
+## 题目
+Given a binary tree, find its minimum depth.
+
+The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
+
+## 解题思路
+
+见程序注释

Algorithms/0111.minimum-depth-of-binary-tree/minimum-depth-of-binary-tree.go

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+package Problem0111
+
+import (
+	"github.com/aQuaYi/LeetCode-in-Golang/kit"
+)
+
+type TreeNode = kit.TreeNode
+
+func minDepth(root *TreeNode) int {
+	if root == nil {
+		return 0
+	}
+
+	if root.Left == nil && root.Right == nil {
+		return 1
+	}
+
+	return max(2, cur(root))
+}
+
+func cur(node *TreeNode) int {
+	if node == nil {
+		return 1
+	}
+
+	return min(minDepth(node.Left), minDepth(node.Right)) +1
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

Algorithms/0111.minimum-depth-of-binary-tree/minimum-depth-of-binary-tree_test.go

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+package Problem0111
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/aQuaYi/LeetCode-in-Golang/kit"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Problem0111(t *testing.T) {
+	ast := assert.New(t)
+
+	// tcs is testcase slice
+	tcs := []struct {
+		pre, in []int
+		ans     int
+	}{
+
+		{
+			[]int{1, 2},
+			[]int{2, 1},
+			2,
+		},
+
+		{
+			[]int{1},
+			[]int{1},
+			1,
+		},
+
+		{
+			[]int{},
+			[]int{},
+			0,
+		},
+
+		{
+			[]int{2, 1, 5, 4, 3, 6, 7},
+			[]int{1, 2, 3, 4, 5, 6, 7},
+			2,
+		},
+
+		{
+			[]int{4, 2, 1, 3, 6, 5, 7},
+			[]int{1, 2, 3, 4, 5, 6, 7},
+			3,
+		},
+
+		// 可以多个 testcase
+	}
+
+	for _, tc := range tcs {
+		fmt.Printf("~~%v~~\n", tc)
+
+		ast.Equal(tc.ans, minDepth(kit.PreIn2Tree(tc.pre, tc.in)), "输入:%v", tc)
+	}
+}