实验七

task4

源代码

#include<stdio.h>
#include<stdlib.h>
int main(){
  FILE *fp;
  int i,n=0,ch;
  int lines=0;
  int newchar='\0';
  fp=fopen("data4.txt","r");
  if(fp==NULL){
      printf("无法打开文件\n");
      return 1;
  }
  while((ch=fgetc(fp))!=EOF){
      if(ch=='\n')
        lines++;

  if(ch!=' '&&ch!='\n'&&ch!='\t')
     n++;
  newchar=ch;

}
 if(newchar!='\n'&&newchar!='\0')
  lines++;
fclose(fp);
printf("data4.txt统计结果：\n");
printf("行数:%d\n",lines);
printf("字符数（不计空白符）：%d\n",n);
system("pause");
return 0;
}

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task5

源代码

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define N 10

typedef struct {
    long id;            // 准考证号
    char name[20];      // 姓名
    float objective;    // 客观题得分
    float subjective;   // 操作题得分
    float sum;          // 总分
    char result[10];    // 考试结果
} STU;

// 函数声明
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: 已完成\n", N);
    read(stu, N);

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

    printf("\n所有考生完整信息:\n");
    output(stu, N);

    printf("\n通过考试的名单写入文件: 已完成!\n");
    write(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);
    system("pause");
    return 0;
}

// 把所有考生完整信息输出到屏幕上
// 准考证号，姓名，客观题得分，操作题得分，总分，结果
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);
}

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

    fin = fopen("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);
}

int process(STU st[], int n, STU st_pass[]){
    int pass_cnt = 0;
     int i;
     for(i=0;i<n;i++)
    {
         st[i].sum = st[i].objective + st[i].subjective;
        if(st[i].sum >= 60)
         {
             strcpy(st[i].result,"通过");
             st_pass[pass_cnt] = st[i];
            pass_cnt++;
         }
         else
         {
             strcpy(st[i].result,"未通过");
         }
     }
     return pass_cnt;
}
 void write(STU st[], int n)
 {
     int i;
     FILE *fp = fopen("list_pass.txt","w");
    fprintf(fp,"%-10s%-10s%-12s%-12s%-10s%s\n",
     "准考证号","姓名","客观题得分","操作题得分","总分","结果");
     for(i=0;i<n;i++)
     {
         fprintf(fp,"%-10ld%-10s%-12.2f%-12.2f%-10.2f%s\n",
         st[i].id,st[i].name,st[i].objective,st[i].subjective,st[i].sum,st[i].result);
     }
     fclose(fp);
    getchar();
     getchar();
 }

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task6

源代码

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define N 80

typedef struct {
    char id[15];
    char name[20];
    char cls[30];
} Student;

int main() {
    Student s[N], lucky[5];
    int flag[N] = {0};
    FILE *fp;
    int i, n = 0;
    int cnt = 0;
    char fname[50];

    fp = fopen("list.txt", "r");
    if (fp == NULL) {
        printf("无法打开 list.txt\n");
        return 1;
    }

    while (fscanf(fp, "%s%s%[^\n]", s[n].id, s[n].name, s[n].cls) != EOF) {
        n++;
    }
    fclose(fp);

    srand(time(NULL));

    while (cnt < 5) {
        int r = rand() % n;
        if (flag[r] == 0) {
            lucky[cnt] = s[r];
            flag[r] = 1;
            cnt++;
        }
    }

    printf("--- 中奖名单 ---\n");
    for (i = 0; i < 5; i++) {
        printf("%s %s %s\n", lucky[i].id, lucky[i].name, lucky[i].cls);
    }

    printf("保存到文件\n");
    printf("输入文件名：");
    scanf("%s", fname);

    fp = fopen(fname, "w");
    if (fp == NULL) {
        printf("文件保存失败\n");
        return 1;
    }

    for (i = 0; i < 5; i++) {
        fprintf(fp, "%s %s %s\n", lucky[i].id, lucky[i].name, lucky[i].cls);
    }
    fclose(fp);

    printf("保存成功！\n");
    system("pause");
    return 0;
}

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