[C#]P1实训学生管理系统

******************************
* 1 学生成绩录入 *
* 2 学生成绩查询 *
* 3 课程成绩分析 *
* 4 退出系统 *
******************************
请选择：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace p1_1022
{
    class Program
    {

        private static int[][] Score;
        private static bool[] bA;

        static void Main(string[] args)
        {
            int iA;//人数

            Console.Write("请输入学生人数：");
            iA = Convert.ToInt32(Console.ReadLine());
            Score = new int[iA][];
            bA = new bool[iA];
            for (int i = 0; i < iA; i++)
            {
                Score[i] = new int[5];
            }
            ///////////////////////////////////////////
            while (true)
            {
                Console.WriteLine("    ******************************");
                Console.WriteLine("    *    1  学生成绩录入         *");
                Console.WriteLine("    *    2  学生成绩查询         *");
                Console.WriteLine("    *    3  课程成绩分析         *");
                Console.WriteLine("    *    4  退出系统             *");
                Console.WriteLine("    ******************************");
                int iB = Convert.ToInt32(Console.ReadLine());
                switch (iB)
                {
                    case 4:
                        return;
                    case 3:
                        if (bA[0] == false)
                        {
                            Console.WriteLine("成绩未录入，不能分析，请重新选择！");
                            break;
                        }
                        Analysis();
                        break;
                    case 2:
                        if (bA[0] == false)
                        {
                            Console.WriteLine("成绩未录入，不能分析，请重新选择！");
                            break;
                        }
                        Query();
                        break;
                    case 1:
                        Console.Write("1、按学号输入 2、按科目输入");
                        iB = Convert.ToInt32(Console.ReadLine());
                        if (iB == 1)
                        {
                            Input();
                            bA[0] = true;
                            break;
                        }
                        if (iB == 2)
                        {
                            G();
                            bA[0] = true;
                            break;
                        }
                        Console.WriteLine("输入不合法，请从新输入！");
                        break;
                    default:
                        Console.WriteLine("输入不合法，请从新输入！");
                        break;
                }

            }
        }
        static void Analysis()
        {
            int iA, iMax, iMin, iSun = 0;
            int[] iB = new int[5];

            Console.WriteLine("请问要按那一科成绩输入（1语文2数学3外语）：");
            iA = Convert.ToInt32(Console.ReadLine());
            iMax = Score[0][iA];
            iMin = Score[0][iA];
            for (int i = 0; i < Score.Length; i++)
            {
                if (Score[i][iA] > iMax)
                {
                    iMax = Score[i][iA];
                }
                if (Score[i][iA] < iMin)
                {
                    iMin = Score[i][iA];
                }
                iSun = iSun + Score[i][iA];


                switch ((int)(Score[i][iA] / 10))
                {
                    case 10:
                    case 9:
                        iB[4]++;
                        break;
                    case 8:
                        iB[3]++;
                        break;
                    case 7:
                        iB[2]++;
                        break;
                    case 6:
                        iB[1]++;
                        break;
                    default:
                        iB[0]++;
                        break;
                }


            }
            Console.WriteLine("最高成绩为：" + iMax);
            Console.WriteLine("最低成绩为：" + iMin);
            Console.WriteLine("平均成绩为：" + iSun / Score.Length);
            Console.WriteLine("分数在90～100人数：" + iB[4]);
            Console.WriteLine("分数在80～89人数：" + iB[3]);
            Console.WriteLine("分数在70～79人数：" + iB[2]);
            Console.WriteLine("分数在60～69人数：" + iB[1]);
            Console.WriteLine("分数在0～59人数：" + iB[0]);



        }//OK
        static void Query()
        {
            int iA = 0;

            while (true)
            {
                Console.WriteLine("请输入要查询的学生学号，输入-1则退出查询！");
                iA = Convert.ToInt32(Console.ReadLine());
                if (iA == -1)
                {
                    break;
                }

                for (int i = 0; i < Score.Length; i++)
                {
                    if (Score[i][0] == iA)
                    {
                        bA[2] = true;
                        Console.WriteLine("------------------------------------------------------");
                        Console.WriteLine("学号\t语文\t数学\t外语\t总分\t");
                        Console.WriteLine("{0}\t{1}\t{2}\t{3}\t{4}", Score[i][0], Score[i][1], Score[i][2], Score[i][3], Score[i][4]);
                    }

                }
                if (bA[2] == false)
                {
                    Console.WriteLine("未查询到该学号！");
                }
                bA[2] = false;
            }
        }//OK
        static void Input()
        {
            for (int i = 0; i < Score.Length; i++)
            {
                Console.WriteLine("请输入学号：");
                Score[i][0] = Convert.ToInt32(Console.ReadLine());
                Console.WriteLine("请输入语文：");
                Score[i][1] = Convert.ToInt32(Console.ReadLine());
                Console.WriteLine("请输入数学：");
                Score[i][2] = Convert.ToInt32(Console.ReadLine());
                Console.WriteLine("请输入外语：");
                Score[i][3] = Convert.ToInt32(Console.ReadLine());
                Score[i][4] = Score[i][1] + Score[i][2] + Score[i][3];
            }
        }//OK
        static void G()
        {
            int iB;
            Console.WriteLine("请问要按那一科成绩输入（1语文2数学3外语）：");
            iB = Convert.ToInt32(Console.ReadLine());
            if (iB == 1 || iB == 2 || iB == 3)
            {
                InputG(iB);
                return;
            }
            Console.WriteLine("输入不合法，请从新输入！");
            return;
        }//OK
        static void InputG(int a)
        {
            for (int i = 0; i < Score.Length; i++)
            {
                Console.WriteLine("请输入学号：");
                Score[i][0] = Convert.ToInt32(Console.ReadLine());
                if (a == 1)
                {
                    Console.WriteLine("请输入语文：");
                }
                if (a == 2)
                {
                    Console.WriteLine("请输入数学：");
                }
                if (a == 3)
                {
                    Console.WriteLine("请输入外语：");
                }
                Score[i][a] = Convert.ToInt32(Console.ReadLine());
            }
        }//OK

    }
}