Add reverse-linked-list-ii

Author: beyondyyh

algorithms/README.md

@@ -24,6 +24,7 @@
 |0069|[x 的平方根](https://leetcode-cn.com/problems/sqrtx/)|[go](./binarysearch/69.mySqrt.go)|S|
 |0071|[简化路径](https://leetcode-cn.com/problems/simplify-path/)|[go](./mystring/71.simplifyPath.go)|M|
 |0078|[子集](https://leetcode-cn.com/problems/subsets/)|[go](./myarray/78.subsets.go)|M|
+|0092|[子集反转链表 II](https://leetcode-cn.com/problems/reverse-linked-list-ii/)|[go](./linkedList/92.reverseBetween.go)|M|
 |0093|[复原IP地址](https://leetcode-cn.com/problems/restore-ip-addresses/submissions/)|[go](./mystring/93.restoreIpAddresses.go)|M|
 |0094|[二叉树的中序遍历](https://leetcode-cn.com/problems/binary-tree-inorder-traversal/)|[go](./tree/94.inorderTraversal.go)|M|
 |0101|[对称二叉树](https://leetcode-cn.com/problems/symmetric-tree/submissions/)|[go](./tree/101.isSymmetric.go)|S|

algorithms/linkedList/92.reverseBetween.go

@@ -0,0 +1,27 @@
+package linkedList
+
+import (
+	_ "fmt"
+
+	_ "Leetcode/algorithms/kit"
+)
+
+func reverseBetween(head *ListNode, m, n int) *ListNode {
+	var dummy *ListNode = &ListNode{Val: 0}
+	dummy.Next = head
+	pre := dummy
+	for i := 1; i < m; i++ {
+		pre = pre.Next
+	}
+
+	curr := pre.Next
+	for i := m; i < n; i++ {
+		next := curr.Next
+		curr.Next = next.Next
+		next.Next = pre.Next
+		pre.Next = next
+
+		// fmt.Printf("m=%d %v\n", m, kit.List2Ints(dummy.Next))
+	}
+	return dummy.Next
+}

algorithms/linkedList/92.reverseBetween_test.go

@@ -0,0 +1,45 @@
+package linkedList
+
+import (
+	"reflect"
+	"testing"
+
+	"Leetcode/algorithms/kit"
+)
+
+type (
+	entry92 struct {
+		name     string
+		input    entry92input
+		expected []int
+	}
+	entry92input struct {
+		ints []int
+		m    int
+		n    int
+	}
+)
+
+// run: go test -v base.go 92.*
+func Test_reverseBetween(t *testing.T) {
+	cases := []entry92{
+		{
+			name:     "x1",
+			input:    entry92input{ints: []int{1, 2, 3, 4, 5}, m: 2, n: 4},
+			expected: []int{1, 4, 3, 2, 5},
+		},
+		{
+			name:     "x2",
+			input:    entry92input{ints: []int{1, 2, 3, 4, 5}, m: 1, n: 5},
+			expected: []int{5, 4, 3, 2, 1},
+		},
+	}
+
+	for _, tc := range cases {
+		head := kit.Ints2List(tc.input.ints)
+		output := kit.List2Ints(reverseBetween(head, tc.input.m, tc.input.n))
+		if !reflect.DeepEqual(output, tc.expected) {
+			t.Errorf("reverseBetween(%v, %d, %d)=%v, expected=%v", tc.input.ints, tc.input.m, tc.input.n, output, tc.expected)
+		}
+	}
+}