实验七

ex3

是；是；是；是

ex4

(1)是；是；否

(2)

#include<stdio.h>
#include <stdlib.h>
#define N 10
// 定义一个结构体类型STU
typedef struct student {
int num;
char name[20];
int score;
}STU;

int main(){

FILE *fin, *fout; // 定义文件类型指针
STU st[N];
int i;

fin = fopen("file4.dat", "rb"); // 以只读文本方式打开文件file4.dat
if(!fin){
printf("Failed to open the file\n");
exit(0);
}

// 从fin指向的数据文件file4.dat中读取数据到结构体数组st
fread(st,sizeof(STU),N,fin);
fclose(fin);


for(i=0; i<N; i++)
fprintf(stdout,"%-6d%-10s%3d\n", st[i].num, st[i].name, st[i].score);


fclose(fout);

return 0;
}

ex5

//task5
#include<stdio.h>
#include<string.h>
#include<stdlib.h>

#define N 10

typedef struct student{
    int num;
    char name[20];
    float kg;
    float zg;
    float sum;
    char level[10];
}STU; 

int main(){
    FILE *fin, *fout;
    int i,j, perfect, pass,min;
    STU s[N];
    
    fin = fopen("6.txt","r");
    if(fin == NULL){
        printf("fail to open 6.txt\n");
        exit(0);
    }
    
    for(i = 0 ; i < N; i++){
        fscanf(fin,"%d %s %f %f",&s[i].num ,s[i].name, &s[i].kg ,&s[i].zg );
        s[i].sum = s[i].kg  + s[i].zg;
    }
    fclose(fin);
    
    STU temp;
    for(i = N - 1 ;i > 0 ; i--){
        j = i - 1;
        min = s[i].sum;
        
        for( ; j >= 0;j--){
        
            if( s[j].sum < min){
                min = s[j].sum;
                temp = s[i];
                s[i] = s[j];
                s[j] = temp;
            }
        
        }
    
    }
    
    perfect = N * 0.1;
    pass = N * 0.5;
    for(i = 0 ; i < N ;i++){
        if(i < perfect ){
            strcpy(s[i].level , "优"); 
        }
        else if(i < pass){
            strcpy(s[i].level , "合格"); 
        }
        else{
            strcpy(s[i].level , "不合格"); 
        }
    }
    
    fout = fopen("7.txt","w");
    if(fout == NULL){
        printf("fail to open 7.txt\n");
        exit(0);
    }
    
    for( i = 0 ; i < N; i++){
        fprintf(fout, "%-6d%-15s%-8.2f%-8.2f%-8.2f%-10s\n",s[i].num,s[i].name,s[i].kg,s[i].zg,s[i].sum,s[i].level);
        printf("%-6d%-15s%-8.2f%-8.2f%-8.2f%-10s\n",s[i].num,s[i].name,s[i].kg,s[i].zg,s[i].sum,s[i].level);
        
    }
    fclose(fout);
    
    return 0;
}