实验7

task 4

#include <stdio.h>

int main() {
    int count = 0;
    char c;
    FILE *fp ;
    fp = fopen("data4.txt", "r");
    
    
    if (fp ==NULL) {
        printf("fail to open the file\n");
        return 1;
    }
    
    while ((c = fgetc(fp)) != EOF) {
        if (c != ' ' && c != '\n' && c != '\t') {
            count++;
        }
    }

    fclose(fp);

    printf("data4.txt中共包含字符数（不计空白符)：%d\n", count);

    return 0;
}

task 5

#include<stdio.h>
#include<string.h>
#define N 10
typedef struct{
    long int id;
    char name[20];
    float objective;
    float subjective;
    float sum;
    char ans[10];
}STU;

void finput(STU st[],int n);
void foutput(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);
     finput(stu,N);

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

     printf("\n通过考试的考生完整信息:\n");
     output(stu_pass,cnt);
     foutput(stu_pass,cnt);

     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].ans);
}

// 从文本文件examinee.txt读入考生信息:准考证号，姓名，客观题得分，操作题得分
void finput(STU st[], int n) {
    int i;
    FILE *fin;

    fin = fopen("examinee.txt", "r");
    if (fin == NULL) {
        printf("fail to open file\n");
        exit(0);
    }

    while (!feof(fin)) {
        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);
}

// 把通过考试的考生完整信息写入文件list_pass.txt
// 准考证号，姓名，客观题得分，操作题得分，总分，结果
void foutput(STU s[], int n) {
    FILE *fout;
    int i;
    
    // 保存到文件 
    fout = fopen("list_pass.txt", "w");
    if (!fout) {
        printf("fail to open or create list_pass.txt\n");
        exit(0);
    }
    
    fprintf(fout, "准考证号\t\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++)
        fprintf(fout, "%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].ans);

    fclose(fout);
}

// 对考生信息进行处理：计算每位考生考试总分、结果；统计考试通过的人数
int process(STU st[], int n, STU st_pass[]) {
   int i,cnt=0;
   for(i=0;i<n;i++){
   st[i].sum=st[i].objective + st[i].subjective;
       if(st[i].sum>=60){
           strcpy(st[i].ans,"pass");
           st_pass[cnt++] = st[i];
       }
       else
       strcpy(st[i].ans,"fail");

   }
    return cnt;
   
   
}

task 6

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#define M 100
#define N 80

typedef struct {
    long int id;
    char name[10];
    char c[20];
}STU;


int main(){
    STU st[M];
    int i,n;
    FILE *fin;
    FILE *fp;

    fin = fopen("list.txt", "r");
    if (fin == NULL) {
        printf("fail to open file\n");
        exit(0);
    }

    while (!feof(fin)){
        for(i=0;i<N;i++)
        fscanf(fin,"%ld %s %s",&st[i].id,st[i].name,st[i].c);
    }

    fp = fopen("lucky.txt", "wb");
    if(fp == NULL) {
        printf("fail to open file\n");
        return 1;
    }

    srand(time(0));
    for(i=0;i<5;i++){
    n=rand()%N;
    fprintf(fp,"%ld %-10s %-20s\n",st[n].id,st[n].name,st[n].c);
    printf("%ld %-10s %-20s\n",st[n].id,st[n].name,st[n].c);
    }

    fclose(fin);
    fclose(fp);
    return 0;
}