4

#include <stdio.h> 
#include <stdlib.h>
#define N 10
typedef struct student {
    int num;
    char name[20];
    int score;
}STU;
void sort(STU *pst, int n);
int main() {
    FILE *fin;
    STU st[N];
    int i;
    fin = fopen("file4.dat", "rb");
    if( !fin ) 
    {
        printf("fail to open file4.dat\n");
        exit(0);
    }
    fread(st,sizeof(STU),N,fin);
    fclose(fin);
    for(i=0;i<N;i++)
        printf("%-6d%-10s%3d\n",st[i].num,st[i].name,st[i].score);
    return 0;
}

#include <stdio.h>
#include<stdlib.h>
#include <string.h>
const int N = 10;
typedef struct student 
{
    long int id;
    char name[20];
    float objective;    
    float subjective;    
    float sum;
    char level[10];    
}STU; 
void input(STU s[], int n);
void output(STU s[], int n);
void process(STU s[], int n);
int main() 
{
    STU stu[N];
    printf("录入%d个考生信息: 准考证号，姓名，客观题得分(<=40)，操作题得分(<=60)\n", N); 
    input(stu, N);
    printf("\n对考生信息进行处理: 计算总分，确定等级\n");
    process(stu, N);
    printf("\n打印考生完整信息: 准考证号，姓名，客观题得分，操作题得分，总分，等级\n");
    output(stu, N); 
    return 0;
} 
void input(STU s[], int n) 
{
    FILE *fin;
    int i;
    fin=fopen("examinee.txt","r"); 
    if(!fin)
    {
        printf("fail to open examinee.txt\n");
        exit(0);
    }
    for(i=0;i<N;i++)
        fscanf(fin,"%d%s%f%f",&s[i].id,&s[i].name,&s[i].objective,&s[i].subjective);
    fclose(fin);
}
void output(STU s[], int n) 
{
    FILE *fout;
    int i;
    fout=fopen("result.txt","w");
    if(!fout)
    {
        printf("fail to open result.txt\n");
        exit(0);
    }
    for(i=0;i<N;i++)
    {
        printf("%-8d%-10s%-8.2f%-8.2f%-8.2f%s\n",s[i].id,s[i].name,s[i].objective,s[i].subjective,s[i].sum,s[i].level);
        fprintf(fout,"%-8d%-10s%-8.2f%-8.2f%-8.2f%s\n",s[i].id,s[i].name,s[i].objective,s[i].subjective,s[i].sum,s[i].level);
    }
    fclose(fout);
}
void process(STU s[], int n) 
{
    STU t;
    int i,j;
    for(i=0;i<n;i++)
    {
        s[i].sum=s[i].objective+s[i].subjective; 
    }
    for(i=0;i<n-1;i++)
    {
        for(j=i+1;j<n;j++)
        {
            if(s[i].sum<s[j].sum)
            {
                t=s[i];
                s[i]=s[j];
                s[j]=t;
            }
        }
    }
    for(i=0;i<n;i++)
    {
        if(i<n/10)
            strcpy(s[i].level,"优秀");
        else if(i<n/2)
            strcpy(s[i].level,"合格");
        else
            strcpy(s[i].level,"不合格");
    }
}