C++ //习题 7.9 写一个函数insert，用来向动态链表插入一个结点。

C++程序设计 （第三版） 谭浩强 习题7.9

习题 7.9 写一个函数insert，用来向动态链表插入一个结点。

IDE工具：VS2010

Note: 使用不同的IDE工具可能有部分差异。

代码块

方法：使用指针，结构体，自定义类型，函数的模块化设计，分配内存

#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

const int N = 3;

//自定义学生类型
typedef struct Student{
	int num;
	string name;
	double score;
	Student *next;
}Student;

//初始化学生并生成头结点，头结点num存储总共学生人数
void initialStu(Student **stu, int n){
	*stu = new Student;
	Student *head = *stu;
	head->num = n;
	head->next = NULL;
}

//链表输入学生信息
void create(Student *stu, int n){
	Student *p = stu->next;
	Student *q = stu;
	cout<<"Enter "<<n<<" Student Info:"<<endl;
	for(int i = 0; i < n; i++){
		p = new Student;
		cout<<"Enter No."<<i + 1<<" Student Number(100 ~ 999): ";
		cin>>p->num;
		while(p->num < 100 || p->num > 999){
			cout<<"Number Error! Retry!\nEnter No."<<i + 1<<" Student Number(100 ~ 999): ";
			cin>>p->num;
		}

		fflush(stdin);
		cout<<"Enter No."<<i + 1<<" Student Name: ";
		getline(cin, p->name);

		cout<<"Enter No."<<i + 1<<" Student Score(0 ~ 100): ";
		cin>>p->score;
		while(p->score < 0 || p->score > 100){
			cout<<"Score Error! Retry!\nEnter No."<<i + 1<<" Student Score(0 ~ 100): ";
			cin>>p->score;
		}

		p->next = NULL;
		q->next = p;
		p = p->next;
		q = q->next;
		cout<<endl;
	}
	cout<<endl;
}

//打印链表学生信息
void print(Student *stu, int n){
	cout<<"Student Info: "<<endl;
	for(Student *p = stu->next; p != NULL; p = p->next){
		cout<<setiosflags(ios::right);
		cout<<"Number: "<<setw(3)<<p->num<<" Name: "<<setw(10)<<p->name<<" Score: ";
		cout<<setiosflags(ios::fixed)<<setprecision(2);
		cout<<setw(5)<<p->score<<endl;
	}
	cout<<endl<<endl;
}

//头插法，插入新增结点
void insert(Student *stu, int n){
	stu->num = n + 1;
	Student *head = stu;

	Student *newStu = new Student;
	cout<<"Enter New Student Number(100 ~ 999): ";
	cin>>newStu->num;
	while(newStu->num < 100 || newStu->num > 999){
		cout<<"Number Error! Retry!\nEnter New Student Number(100 ~ 999): ";
		cin>>newStu->num;
	}

	fflush(stdin);
	cout<<"Enter New Student Name: ";
	getline(cin, newStu->name);

	cout<<"Enter New Student Score(0 ~ 100): ";
	cin>>newStu->score;
	while(newStu->score < 0 || newStu->score > 100){
		cout<<"Score Error! Retry!\nEnter New Student Score(0 ~ 100): ";
		cin>>newStu->score;
	}
	newStu->next = head->next;
	head->next = newStu;
}

int main(){
	Student *stu = NULL;

	initialStu(&stu, N);
	create(stu, N);
	print(stu, N);
	insert(stu, N);
	print(stu, N);

	delete stu;
	
	system("pause");
    return 0;
}