//综合实践七：学生成绩管理系统指针应用设计

#include<stdio.h>

#define N 5

int login(char *name,char *psw){

if(strcmp(name,"admin")==0 &&strcmp(psw,"123456")==0)

    return 1;

else return 0;

}

void input(float *score,int num){

int i;

printf("输入%d个成绩：",num);

for(i=0;i<num;i++){

    scanf("%f",score++);

}

}

void output(float *score,int num){

int i;

printf("输出%d个成绩：\n",num);

for(i=0;i<num;i++){

    printf("%5.1f",*score++);

}

printf("\n");

}

int insert(float *score,int num,float x){

int i;

i=num-1;

    while(i>=0&&*(score+i)<x){

       *(score+i+1)=*(score+i);

       i--;

}

    *(score+i+1)=x;

    num++;

    return num;

}  

int find(float *score,int num,float x){

int i,k=-1;

for(i=0;i<num;i++){

       if(x==*(score+i)){

       k=i;

       break;

   }     

    }

    return k;   

}

void sort(float *score,int num){

int i,j,k;

float x;

for(i=0;i<num-1;i++){

        k=i;

        for(j=i+1;j<num;j++){

            if(*(score+k)<*(score+j))

            k=j;

}

        x=*(score+i);

        *(score+i)=*(score+k);

        *(score+k)=x;

}

printf("降序排序完成！\n");

}

int dele(float *score,int num,float x){

int i=0;

while(i<num&&*(score+i)!=x){

       i++;

}

if(i<num){

  while(i<num-1){

  *(score+i)=*(score+i+1);

  i++;

    }

    num--;

}

return num;

}

main(){

   float score[N],max,s,x,ave;

   int i,j,k,n,num,m;

   char name[10],psw[10];

   printf("用户名:");

   gets(name);

   printf("密码:");

   gets(psw);

   if(login(name,psw)==1){

   while(1){

printf("******学生成绩管理系统********\n");

printf("***  1 --------- 成绩输入  **\n" );

printf("***  2 ----------成绩插入  **\n ");

printf("***  3  ---------成绩查询  **\n ");

printf("***  4  ---------成绩排序  **\n ");

    printf("***  5  ---------成绩删除  **\n ");

    printf("***  6  ---------成绩输出  **\n ");

printf("***  0  ---------退出      **\n ");

printf("*****************************\n");

printf("请输入你的选择：");

scanf("%d",&n);

switch(n){

   case 1:printf("输入成绩个数(<%d)：",N);

          scanf("%d",&num);

          input(score,num);

      break;

   case 2:printf("输入要插入的成绩：");

              scanf("%f",&x);

              num=insert(score,num,x);

              break;

   case 3:printf("输入要查询的成绩：");

              scanf("%f",&x);

              m=find(score,num,x);

              if(m!=-1)

                  printf("序号：%d\n",m+1);

              else printf("成绩不存在！\n");

      break;

   case 4:sort(score,num);

      break;

   case 5:printf("输入要删除的成绩：");

              scanf("%f",&x);

              m=num;

              num=dele(score,num,x);

              if(m!=num)

                  printf("成绩删除成功！\n");

  else printf("成绩不存在！\n");

              break;

       case 6:printf("成绩输出：");

          output(score,num);

      break;

   case 0:return;

   default:printf("选择错误！\n");

    }}}

    else printf("用户名或密码错误！\n");

}