实验七

task4

#include<stdio.h>
#include<ctype.h>

int main(){
    int line=0,chars=0,ch;
    FILE *fp;
    
    fp=fopen("C:\\Users\\ZhuanZ（无密码）\\Desktop\\实验7数据文件及部分代码_gbk\\data4.txt","r");
    printf("data4.txt统计结果:\n");
    if(!fp){
        perror("data4.txt");
        return 1;
    }
    while((ch=fgetc(fp))!=EOF){
        if(!isspace(ch)){
            chars++;
        }
    if(ch=='\n'){
        line++;
    }
}
    ch=fgetc(fp);
    if(ch!='\n')
    line++;
    
    fclose(fp);
    printf("字符数：%d\n",chars);
    printf("行数：%d",line);
    return 0;
}

 ```

task5

#include <stdio.h>
#include <string.h>

#define N 10

typedef struct {
    long id;            
    char name[20];      
    float objective;    
    float subjective;   
    float sum;         
    char result[10];   
} STU;

void read(STU st[], int n);
void write(STU st[], int n);
void output(STU st[], int n);
int process(STU st[], int n, STU st_pass[]);

int main() {
    STU stu[N], stu_pass[N];
    int cnt;
    double pass_rate;

    printf("从文件读入%d个考生信息...\n", N);
    read(stu, N);

    printf("\n对考生成绩进行统计...\n");
    cnt = process(stu, N, stu_pass);

    printf("\n通过考试的名单:\n");
    output(stu, N);   
    write(stu, N);   

    pass_rate = 1.0 * cnt / N;
    printf("\n本次等级考试通过率: %.2f%%\n", pass_rate*100);

    return 0;
}

void output(STU st[], int n) {
    int i;
    
    printf("准考证号\t姓名\t客观题得分\t操作题得分\t总分\t\t结果\n");
    for (i = 0; i < n; i++)
        printf("%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", st[i].id, st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].result);
}

void read(STU st[], int n) {
    int i;
    FILE *fin;

    fin = fopen("C:\\Users\\ZhuanZ（无密码）\\Desktop\\实验7数据文件及部分代码_gbk\\examinee.txt", "r");
    if (!fin) {
        printf("fail to open file\n");
        return;
    }

    for (i = 0; i < n; i++)
        fscanf(fin, "%ld %s %f %f", &st[i].id, st[i].name, &st[i].objective, &st[i].subjective);

    fclose(fin);
}

void write(STU st[], int n) {
    int i,j;
    FILE *fp;
    
   fp=fopen("C:\\Users\\ZhuanZ（无密码）\\Desktop\\实验7数据文件及部分代码_gbk\\list_pass.txt","w");
    
    if(fp==NULL){
        printf("fail to open file to write\n");
        return;
    }
    for(i=0;i<n;++i)
    if(st[i].result=="通过"){
        st[j]=st[i];
        j++; 
}
    for(i=0;i<n;++i)
    fprintf(fp,"%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", st[j].id, st[j].name, st[j].objective, st[j].subjective,st[j].sum, st[j].result);
     fclose(fp);
}

int process(STU st[], int n, STU st_pass[]) {
    int i,count=0;
    for(i=0;i<n;i++){
        st[i].sum=st[i].objective+st[i].subjective;
        if(st[i].sum>=60){
            st_pass[count]=st[i];
            count++;
            strcpy(st[i].result,"通过");
        }
        else
        strcpy(st[i].result,"未通过");
    }
    return count;
}

```

task6

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 100

int main()
{
    char s[N][N];
    FILE *fp,*fp_out;
    int i,n;
    
    fp=fopen("C:\\Users\\ZhuanZ（无密码）\\Desktop\\实验7数据文件及部分代码_gbk\\list.txt","r");
    if(!fp){
        perror("list.txt");
        return 1;
    }
    i=0;
    while(fgets(s[i],N,fp)!=NULL)
    ++i;
    n=i;
    
    char filename[N];
    printf("输入文件名：");
    scanf("%s",&filename);
    fp_out=fopen(filename,"w");
    if(!fp_out){
        perror(filename);
        return 1;
    }
    
    int t;
    int flag[N]={0};
    srand(time(NULL));
    for(i=0;i<5;++i){
    do{
    t=rand()%81;
}
    while(flag[t]==1);
        flag[t]=1;
    printf("%s",s[t]);
    fprintf(fp_out,"%s",s[t]);

}
    fclose(fp_out);
    return 0;
    
}