简易学生信息管理系统

最近在复习 《数据结构》 线性表。今天耗费了整个下午加上晚上1个多小时的调整写出来一个小程序。诶，不得不感叹，代码什么的还是要经常写啊。

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这个  《简易学生信息管理系统》 的功能如下：

1、能够输入、输出、删除、更新、排序信息；

2、学生的信息包括：姓名（10个字符）、ID（0～32767）、分数（0～150）

3、ID不允许重复（貌似忘记限制ID小于零的情况和分数超过范围了。 XP）

4、学生的人数上限是10个（额，这个可以多一点）

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程序编译、运行的环境：

ubuntu 12.04.2LTS ; Linux  3.5.0-36-generic ; gcc version 4.6.3； Vi IMproved 7.3 

//This program is about managing students' info.

#include <stdio.h>
#include <string.h>
typedef struct{
	char name[10];
	int	id;
	int score;
}Info;


void Menu();
int Add_Info(Info *stu);
void Print(Info *stu);
void Del(Info *stu );
void Sort(Info *stu);
void Update(Info *stu );
void Menu_Quit();

int num=0;

void main(){
	Info stu[10];
	int flag=1;
	char choise;
	Menu();
	while(flag==1){
		scanf (" %c",&choise);
		switch(choise){
				case 'a':	Add_Info(stu);	Menu();	break;
				case 'd':	Del(stu);	Menu();	break;
				case 's':	Sort(stu);	Menu();	break;
				case 'u':	Update(stu);	Menu();	break;
				case 'p':	Print(stu);	Menu();	break;
				case 'q':	flag=0;	Menu_Quit();	break;
				default:
					printf ("Sry,input Error!Plz Input again:");
		}
	}
}

void Menu(){
	system("clear");
	printf ("\n\n Practice\n\n");
	printf ("==================================\n\n");
	printf ("a.Add info            d.Del info\n");
	printf ("u.Update info         p.Print info\n");
	printf ("s.Sort                q.Quit\n");
	printf ("\n\n==================================\n");
	printf ("\nPlease input your choise:___\b\b");
}

int Add_Info(Info *stu){
	printf ("You have choosed \"a\"!\n");
	int i,j,numtmp=0,num1=0,num2=0;
	Print(stu);
	printf ("How many students:");
	scanf ("%d",&numtmp);
	if (num>10 || numtmp>10){
		printf ("Sry,Overflow!!Plz try another way!\n");
		return  0;
	}
	if (num){
		num1=num;
		num2=numtmp+num;
	}
	else{
		num1=0;
		num2=numtmp;
	}
	for (i=num1;i<num2;i++){
		getchar();
		printf ("==============================\n");
		printf ("Plz input the %dst's name:",i+1);
		gets(stu[i].name);
		printf ("Plz input the %dst's id:",i+1);
		scanf ("%d",&stu[i].id);
	
		//IDs CANNOT repeat
		if (num){
			for (j=0;j<i;){
				if (stu[j].id==stu[i].id){
					printf ("Error!ID repeated!!Plz input again:");
					scanf ("%d",&stu[i].id);
					j=0;
				}
				else
					j++;
			}
		}
	
		printf ("Plz input the %dst's score:",i+1);
		scanf ("%d",&stu[i].score);
		num++;
	}
	printf ("\nDone with the input!\n");
	printf ("Here's the new Database:\n");
	Print(stu);
	return 1;
} 

void  Print(Info *stu){
	int i;
	printf ("\nThere're %d students' info in the database\n",num);
	printf ("Name    ID    Score\n");
	printf ("===================\n");
	for (i=0;i<num;i++){
		printf ("%s%6d%9d\n",stu[i].name,stu[i].id,stu[i].score);
	}
	printf ("===================\n\n");
	printf ("press ANY key to continue");
	getchar();
	getchar();
}
 
void Del(Info *stu ){
	int i,j,id,flag=0;
	printf ("You have choised \"d\"!\n");
	Print(stu);
	printf ("Plz input the student's id that you want to delete:");
	while (flag==0){
		scanf ("%d",&id);
		for (i=0;i<num;i++){
			if (stu[i].id==id){
				printf ("Found the student!! Deleting Info, plz wait...\n");
				for (j=i;j<num-1;j++){
					strcpy(stu[j].name,stu[j+1].name);
					stu[j].id=stu[j+1].id;
					stu[j].score=stu[j+1].score;
				}
				flag=1;			
				system("sleep 1");
			}
		}
		if (flag==0)
			printf ("Wrong ID!Plz input again:");
	}
	num--;
	printf ("\nDone with the delete!\n");
	printf ("Here's the new Database:\n");
	Print(stu);
} 

void Update(Info *stu ){
	int id,i,j,flag=0;
	printf ("You have choosed \"u\"! !\n");	
	Print(stu);
	printf ("Plz input the student's id that you want to update:");
	while (flag==0){
		scanf ("%d",&id);
		for (i=0;i<num;i++){
			if (stu[i].id==id){
				printf ("Found the student!!\n");
				printf ("Plz input ID:%d's name:",id);
				getchar();
				gets(stu[i].name);
				printf ("Plz input ID:%d's score:",id);
				scanf ("%d",&stu[i].score);
				flag=1;			
			}
		}
		if (flag==0)
			printf ("Wrong ID!Plz input again:");
	}
	printf ("\nDone with the update!\n");
	printf ("Here's the new Database:\n");
	Print(stu);
} 

void Sort(Info *stu){
	printf ("You have choosed \"s\"!\n");
	Print (stu);
	printf ("Sort by 1.ID; 2.Score:");
	int choise,flag=0,i,j;
	Info tmp;
	while(flag==0){
		scanf ("%d",&choise);
		switch(choise){
			case 1://id
				for (i=0;i<num-1;i++){
					for (j=i+1;j<num;j++){
						if (stu[i].id>stu[j].id){
							strcpy(tmp.name,stu[i].name);
							tmp.id=stu[i].id;
							tmp.score=stu[i].score;

							strcpy(stu[i].name,stu[j].name);
							stu[i].id=stu[j].id;
							stu[i].score=stu[j].score;

							strcpy(stu[j].name,tmp.name);
							stu[j].id=tmp.id;
							stu[j].score=tmp.score;
						}
					}
				}
				Print(stu);
				flag=1;
				break;
			case 2://score
				for (i=0;i<num-1;i++){
					for (j=i+1;j<num;j++){
						if (stu[i].score<stu[j].score){
							strcpy(tmp.name,stu[i].name);
							tmp.id=stu[i].id;
							tmp.score=stu[i].score;

							strcpy(stu[i].name,stu[j].name);
							stu[i].id=stu[j].id;
							stu[i].score=stu[j].score;

							strcpy(stu[j].name,tmp.name);
							stu[j].id=tmp.id;
							stu[j].score=tmp.score;
						}
					}
				}
				Print(stu);
				flag=1;
				break;
			default:
				printf ("Wrong Choise!Plz input again:");
		}
	}
}

void Menu_Quit(){
	printf ("\n\n##################################\n");
	printf (" This is the END of this program!\n");
	printf (" Thanks for trial!     Good luck!\n");
	printf ("##################################\n");
}

心得：

这样的程序虽然才200多行，不过还是有点小复杂。写的时候得先把框架打好，需要些什么功能，构建什么样的函数；用一些什么样的变量；注意细节，代码多了，很容易出错，调试起来很麻烦，这个只能得多写多练才能提高。

总结：

诶，勉强能拼凑出相应的功能。至于什么样的算法、结构更加简单、快速；怎样优化内存的使用；如果数据是几千几万怎么弄等等，这样的问题，现在的我还解决不了。只能考以后的学习来慢慢弥补啦。