char13.9.c

c语言版的学生成绩管理系统

#include<stdio.h>
struct student{
    char number[3];
    char name[10];
    int score[3];
    float avrg;
}std[10];
void sort(){
    int i;
    int k;
    int j;
    struct student temp;

    for(i=0;i<3;i++){
        k=i;
        for(j=i+1;j<3;j++){
            if(std[k].avrg>std[j].avrg)
                k=j;
        }
        if(k!=i){
            temp=std[i];
            std[i]=std[k];
            std[k]=temp;
        }
    }
}

void store(int n){

    FILE  *file;
    file=fopen("stud","wb");
    if(file==NULL)
        printf("can't open file in the store");

    int i;
    for(i=0;i<n;i++)
        fwrite(&std[i],sizeof(struct student),1,file);
    fclose(file);
}

void read(int n){

    int i;
    FILE *file;
    file=fopen("stud","rb");
    if(file==NULL)
        printf("can't open file in read\n");

    for(i=0;i<n;i++)
        fread(&std[i],sizeof(struct student),1,file);
    fclose(file);
}

void pnt(int n){
    int i;
    int j;

    for(i=0;i<n;i++){
        printf("%s  %s  ",std[i].number,std[i].name);
        for(j=0;j<3;j++)
            printf("%d  ",std[i].score[j]);
    }
}

main(){
    int i;
    int j;
    float sum;
    printf("please enter 3 students data\n");

    for(i=0;i<3;i++){
        sum=0;
        scanf("%s%s",std[i].number,std[i].name);
        for(j=0;j<3;j++){
            scanf("%d",&std[i].score[j]);
            sum+=std[i].score[j];
         }
        std[i].avrg=sum/3.0;
    }

    sort();    
    store(3);
    printf("NO. Name Score1 Score2 Score3\n");
    pnt(3);
   
    struct student temp;
    printf("please enter the new student data\n");
    scanf("%s%s",temp.number,temp.name);
    scanf("%d%d%d",&temp.score[0],&temp.score[1],&temp.score[2]);
    temp.avrg=(temp.score[0]+temp.score[1],temp.score[2])/3.0;
  
    read(3);
    int flag=0;
    FILE *file;
    file=fopen("new_std","rb");
    if(file==NULL){
        printf("can't open file when insert new node\n");
        exit(0);
    }

    for(i=0;i<3;i++){
        if(temp.avrg<std[i].avrg&&flag==0){
            fwrite(&temp,sizeof(struct student),1,file);
            flag=1;
            i-=1;
            continue;
        }
        fwrite(&std[i],sizeof(struct student),1,file);
    }
    fclose(file);

    
    file=fopen("new_std","rb");
    if(file==NULL){
        printf("can't read from new_std\n");
        exit(0);
    }
    
    printf("NO. Name Score1 Score2 Score3\n");
    pnt(4);
    fclose(file);
}