code kata 230829

code_kata_230829/move_list_test.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+)
+
+func moveList(k int, head *node) {
+	printList(head)
+	if head == nil {
+		return
+	}
+	cnt := head.Len()
+	if k == cnt || k == 0 {
+		return
+	}
+
+	p := head
+	var r *node
+	if k > cnt {
+		k = k % cnt
+	}
+	for i := 0; i < k; i++ {
+		r = p
+		p = p.next
+	}
+	r.next = nil
+	printList(p)
+	printList(head)
+	r = head
+	head = p
+	for p != nil && p.next != nil {
+		p = p.next
+	}
+	p.next = r
+	printList(head)
+}
+
+func TestMoveList(t *testing.T) {
+	moveList(4, makeList1())
+	moveList(0, makeList1())
+	moveList(2, makeList2())
+	moveList(5, makeList2())
+}
+
+func printList(head *node) {
+	for head != nil {
+		fmt.Printf("%d->", head.value)
+		head = head.next
+	}
+	fmt.Println("nil")
+}
+
+func makeList2() *node {
+	return &node{
+		next: &node{
+			next: &node{
+				next: &node{
+					next: &node{
+						value: 4,
+					},
+					value: 3,
+				},
+				value: 2,
+			},
+			value: 1,
+		},
+		value: 0,
+	}
+}
+
+func makeList1() *node {
+	return &node{
+		next: &node{
+			next: &node{
+				value: 2,
+			},
+			value: 1,
+		},
+		value: 0,
+	}
+}
+
+type node struct {
+	value int
+	next  *node
+}
+
+func (n *node) Len() int {
+	ret := 0
+	p := n
+	for p != nil {
+		p = p.next
+		ret++
+	}
+	return ret
+}