实验7_文件应用编程

4.task_4

 

#include <stdio.h>
#include <string.h>
#define N 10000

int main()
{
    int count,i,t=0;
    char x[N];
    FILE *fp;
    fp=fopen("D:\\data4.txt","r");
    while (!feof(fp))
    {
        fgets(x,N,fp);
        count=strlen(x);
        if (x[count-1]=='\n')
        {
            x[count-1]='\0';
            count--;
        }
        for (i=0;x[i]!='\0';i++)
        {
            if (x[i]==' ')
                count--;
        }
        t+=count;
    }
    fclose(fp);
    printf("data4.txt中共包含字符数（不计空白字符）：%d\n",t);
    return 0;
}

 

5.task_5

#include <stdio.h>
#include <string.h>
#include <stdlib.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通过考试的名单:\n");
    output(stu, N);
    foutput(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].ans);
}

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

    fin = fopen("D:\\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);
}

void foutput(STU s[], int n) {
    FILE *fout;
    int i;
    
    fout = fopen("D:\\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);
}
 
int process(STU st[], int n, STU st_pass[]) {
    int i,j;
    for (i=0,j=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[j++]=st[i];
        }
        else
            strcpy(st[i].ans,"fail");
    }
    return j;
}

 

6.task_6

 

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

typedef struct
{
    long int id;
    char name[N];
    char class[N];
}STU;

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

int main()
{
    int i,k;
    STU stu[N],lucky[N];
    finput(stu,N);
    for (i=0;i<5;i++)
    {
        k=rand()%80;
        lucky[i]=stu[k];
    }
    foutput(lucky);
    for (i=0;i<5;i++)
        printf("%ld\t\t%s\t\t%s\n",lucky[i].id,lucky[i].name,lucky[i].class);
    return 0;
}

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

    fin = fopen("D:\\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].class);
    }

    fclose(fin);
    
}

void foutput(STU st[N])
{
    int i;
    FILE *fout;
    fout = fopen("D:\\lucky.txt", "w");
    if (!fout) {
        printf("fail to open or create lucky.txt\n");
        exit(0);
    }
    for (i=0;i<5;i++)
        fprintf(fout,"%ld\t\t%s\t\t%s\n",st[i].id,st[i].name,st[i].class);
    fclose(fout);
}