《Go語言程序設計》第8章練習

8.1 班上有30個學生，每個學生的信息包括學號、姓名、性別、年齡、三門課的成績。要求建立學生信息的結構體student，輸入這30個學生的信息，然後打印輸出各項數據。

package main

import (
	"fmt"
)

type student struct {
	num   string
	name  string
	sex   string
	age   int
	score [3]float32
}

func main() {
	var stu [30]student
	for i := 0; i < len(stu); i++ {
		fmt.Scan(&stu[i].num, &stu[i].name, &stu[i].sex, &stu[i].age, &stu[i].score[0], &stu[i].score[1], &stu[i].score[2])
	}
	for _, v := range stu {
		v.print()
	}

}

func (stu *student) print() {
	fmt.Println("學號:", stu.num)
	fmt.Println("姓名:", stu.name)
	fmt.Println("年齡：", stu.age)
	fmt.Println("性別：", stu.sex)
	fmt.Println("數學:", stu.score[0])
	fmt.Println("語文：", stu.score[1])
	fmt.Println("英語：", stu.score[2], "\n")
}

8.2 有4名學生，每個學生包括學號、姓名、成績，編寫函數找出成績最高學生的學號、姓名和成績。

package main

import (
	"fmt"
)

type student struct {
	num   string
	name  string
	score float32
}

func main() {
	var stu = [4]student{{"001", "Tom", 90}, {"002", "Jim", 77}, {"003", "Pony", 99}, {"004", "Lily", 90}}
	var max float32 = stu[0].score
	var index int
	for i, v := range stu {
		if max < v.score {
			max = v.score
			index = i
		}
	}
	fmt.Println(stu[index])
}

8.4 有一批圖書，每本書有書名、作者、書號、出版日期4項數據，希望既可以通過書名查詢，也可以使用作者或書名來查詢圖書。編寫方法來實現此功能，如果查到，打印出此書的書名、作者、書號和出版日期信息。如果查不到此書，則打印出“無此書”。

package main

import (
	"errors"
	"fmt"
	"strings"
)

type Book struct {
	Name   string
	Author string
	Isdn   string
	Date   string
}

func main() {
	var books = []Book{
		{"Clojure程序設計", "Aaron Bedra", "9787115308474", "2013年4月"},
		{"Go語言程序設計", "王鵬", "9787302347231", "2014年1月"},
		{"TCP Sockets編程", "Jesse Stirumer", "9787115330529", "2013年10月"},
		{"Haskell趣學指南", "Miran Lipovaca", "9787115335593", "2014年1月"}}
	for {
		var field, value string
		switch menu() {
		case 1:
			field = "name"
			fmt.Print("請輸入書名：")
			fmt.Scan(&value)
		case 2:
			field = "author"
			fmt.Print("請輸入作者：")
			fmt.Scan(&value)
		case 3:
			field = "isdn"
			fmt.Print("請輸入ISDN：")
			fmt.Scan(&value)
		default:
			return
		}
		if b, err := find(books, field, value); err == nil {
			fmt.Println(b)
		} else {
			fmt.Println(err)
		}
	}
}

func find(books []Book, field, value string) (b Book, err error) {
	for _, v := range books {
		if v.IsMatch(field, value) {
			return v, nil
		}
	}
	return b, errors.New("無此書")
}

func (b *Book) IsMatch(field, value string) (r bool) {
	switch field {
	case "name":
		r = strings.Contains(b.Name, value)
	case "author":
		r = strings.Contains(b.Author, value)
	case "isdn":
		r = strings.Contains(b.Isdn, value)
	default:
		r = false
	}
	return
}

func menu() int {
	fmt.Println("1.根據書名查詢")
	fmt.Println("2.根據作者查詢")
	fmt.Println("3.根據書號查詢")
	fmt.Println("4.退出")
	fmt.Print("請選擇：")
	var choice int
	fmt.Scan(&choice)
	return choice
}

8.5 有兩個單鏈表a,b。設節點中包含學號、姓名。從鏈表a中刪除所有與鏈表b中學號相同的節點。

package main

import (
	"fmt"
)

type Student struct {
	Id   int
	Name string
}

type Node struct {
	Student
	Next *Node
}

type LinkList struct {
	head *Node
	tail *Node
}

func main() {
	var link, another *LinkList
	var stu = [4]Student{{1, "Timi"}, {2, "Jack"}, {3, "Lucy"}, {4, "Lily"}}

	link = link.Create()
	for _, v := range stu {
		link.Add(v)
	}
	fmt.Print("LinkList A:")
	link.Print()

	another = another.Create()
	another.Add(stu[0])
	another.Add(stu[1])
	another.Add(stu[3])
	fmt.Print("\nLinkList B:")
	another.Print()

	link.Diff(another)
	fmt.Print("\nA-B:")
	link.Print()
}

func (link *LinkList) Create() *LinkList {
	link = new(LinkList)
	link.head = nil
	link.tail = nil
	return link
}

func (link *LinkList) Add(stu Student) {
	if link == nil {
		return
	}
	var node = new(Node)
	node.Id = stu.Id
	node.Name = stu.Name
	node.Next = nil
	if link.head != nil {
		link.tail.Next = node
		link.tail = node
	} else {
		link.head = node
		link.tail = node
	}
}

func (link *LinkList) Del(index int) {
	if link.head == nil {
		return
	}
	if index == 0 {
		if link.head.Next == nil {
			link.head = nil
			link.tail = nil
		} else {
			link.head = link.head.Next
		}
		return
	}
	p := link.head
	for i := 0; i < index-1 && p != nil; i++ {
		p = p.Next
	}
	if p.Next != nil {
		p.Next = p.Next.Next
	} else {
		p.Next = nil
		link.tail = p
	}
}

func (link *LinkList) Diff(another *LinkList) {
LOOP:
	p1 := link.head
	var index int
	for p1 != nil {
		p2 := another.head
		for p2 != nil {
			if p1.Id == p2.Id {
				link.Del(index)
				goto LOOP
			}
			p2 = p2.Next
		}
		index++
		p1 = p1.Next
	}
}

func (link *LinkList) Print() {
	p := link.head
	for p != nil {
		fmt.Printf("%v->", p.Student)
		p = p.Next
	}
	fmt.Print("nil")
}