实验七

task 4

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


int main()
{
    FILE *fp;
    
    
    fp = fopen("data4.txt","r");
    if(fp==NULL){
        printf("fail to open file\n");
        return 1;
    }
    int t = 0;
    char h;
    while(1){
        h = fgetc(fp);
        if(h==EOF)
         break;
        else if(h==' '||h=='\n')
         continue;
        else
         t++;
    }
    printf("文件内字符数为(不计空白符)%d\n",t);
    
    fclose(fp);
    return 0;
 } 

task 5

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

#define N 10

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

// 函数声明
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通过考试的名单:\n");
    output(stu, N);      // 输出到屏幕
    foutput(stu, N);    // 输出到文件

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

    return 0;
}

// 把通过考试的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].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[]) {
    FILE *fpass;
    int cnt = 0;
    int i;
    fpass = fopen("list_pass.txt","r");
    for(i = 0;i<n;++i){
        st[i].sum = st[i].objective+st[i].subjective;
    }
    for(i = 0;i<n;++i){
        if(st[i].sum>=60){
            strcpy(st[i].ans,"pass");
            cnt++;
        }
        else{
            strcpy(st[i].ans,"fail");
        }
    }
    return cnt;
}

task 6

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

typedef struct{
    long int num;
    char name[10];
    char clas[20];
} student;

int main()
{
    FILE *fp,*f;
    fp = fopen("list.txt","r");
    if(fp==NULL){
        printf("fail to open file\n");
        return 1;
    }
    int i,cnt,n;
    srand(time(NULL));
    student st[100];
    student lucky[5];
    
    while(!feof(fp)){
        for(i = 0;i<100;i++){
            fscanf(fp,"%ld %s %s",&st[i].num,st[i].name,st[i].clas);
        }
    }
    cnt = sizeof(st)/sizeof(student);
    
    f = fopen("lucky.txt","w");
    for(i = 0;i<5;++i){
        n = rand()%cnt;
        fprintf(f,"%-20ld%-20s%-30s",st[n].num,st[n].name,st[n].clas);
        fprintf(f,"\n");
        lucky[i] = st[n];
        printf("%-20ld%-20s%-30s\n",lucky[i].num,lucky[i].name,lucky[i].clas);
    }
    fclose(fp);
    fclose(f);
    return 0;
 }