c++笔试题：简易学生信息系统

//姓名       学号         成绩

#include <iostream>
#include <string.h>
using namespace std;

struct student
{
	char name[10];
	int num;
	float score;
};
class studentlist
{
public:
	studentlist()
	{
		len = 0;
	}
	void Insert(char *inputstr)
	{
		if (len >= 40)
		{
			cout << "学生已经满了！" << endl;
			return;
		}
		char *p = strtok(inputstr, " ");
		if (strlen(p) >= 10)
		{
			cout << "姓名输入错误！" << endl;
			return;
		}
		else
		{
			strcpy(v[len].name, p);
		}
		p = strtok(NULL, " ");
		if (strlen(p) > 7)
		{
			cout << "学号输入有误！" << endl;
			return;
		}
		else
		{
			v[len].num = atoi(p);
		}
		p = strtok(NULL, "\n");
		if (strlen(p) > 3)
		{
			cout << "成绩输入有误！" << endl;
			return;
		}
		else
		{
			v[len].score = atof(p);
		}
		len++;
		cout << "插入新的同学成功!" << endl;
	}
	void Delete(char *_name)
	{
		for (int i = 0; i < len; ++i)
		{
			if (strcmp(_name, v[i].name) == 0)
			{
				for (int j = i; j < len - 1; ++j)
				{
					strcpy(v[j].name, v[j + 1].name);
					v[j].num = v[j + 1].num;
					v[j].score = v[j + 1].score;
				}
				cout << "删除同学成功！" << endl;
				len--;
				return;
			}
		}
		cout << "没有找到这个同学哦！"<<endl;
	}
	void Sort()
	{
		student stu;
		//用的冒泡排序。
		for (int i = 0; i < len-1; ++i)
		{
			for (int j = i+1; j < len; ++j)
			{
				if (v[i].score < v[j].score)
				{
					strcpy(stu.name, v[i].name);
					stu.num = v[i].num;
					stu.score = v[i].score;

					strcpy(v[i].name,v[j].name);
					v[i].num = v[j].num;
					v[i].score = v[j].score;

					strcpy(v[j].name, stu.name);
					v[j].num = stu.num;
					v[j].score = stu.score;
				}
			}
		}
	}
	void Printf()
	{
		cout << "姓名\t" << "学号\t" << "成绩"<<endl;
		for (int i = 0; i < len; ++i)
		{
			cout << v[i].name << "\t" << v[i].num << "\t" << v[i].score << endl;
		}
	}
private:
	struct student v[40];
	int len;
};
int main()
{
	int flags = 1;
	studentlist list;
	while (flags)
	{
		cout << "输入数字1插入学生信息" << endl;
		cout << "输入数字2打印学生信息" << endl;
		cout << "输入数字3删除学生信息" << endl;
		cout << "输入数字4排序学生成绩" << endl;
		cout << "输入数字0退出学生信息" << endl;
		cout << "请输入你的选择:>" << endl;
		cin >> flags;
		switch (flags)
		{
		case 1:
			cout << "请输入学生信息：>" << endl;
			char input[30];
			cin.get();
			cin.get(input,30);//不要最后的"\n"。
			cin.get();
			list.Insert(input);
			break;
		case 2:
			list.Printf();
			break;
		case 3:
			char name[10];
			cin >> name;
			list.Delete(name);
			break;
		case 4:
			list.Sort();
			break;
		default:
			break;
		}
	}
	return 0;
}