实验七

实验任务4

源代码

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

int main(){
    FILE *fp;
    char ch;
    int line_count=0;
    int char_count=0;
    int is_new_line=1;

    fp=fopen("data4.txt","r");
    if(fp==NULL){
        printf("无法打开文件data.txt\n");
        return 1;
    }

    while((ch=fgetc(fp))!=EOF){

        if(ch=='\n'){
            line_count++;
            is_new_line=1;
        }

        if(!isspace(ch)){
            char_count++;
        }
    }

    if(!is_new_line){
        line_count++;
    }

    fclose(fp);

    printf("data4.txt 统计结果：\n");
    printf("行数：\t\t\t%d\n字符数（不计空白符）：\t%d\n",line_count,char_count);
    
    system("pause");

    return 0;
}

运行结果截图

实验任务5

源代码

 

#include <stdio.h>
#include <string.h>
#include <stdlib.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：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;
}


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("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 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].result, "通过");
            st_pass[cnt] = st[i];
            cnt++;
        }
        else
        {
            strcpy(st[i].result, "不通过");
        }
    }
    return cnt;
}


void write(STU st[], int n)
{
    int i;
    FILE *fp;
    fp = fopen("list_pass.txt","w");
    for(i = 0; i < n; i++)
    {
        fprintf(fp,"%ld\t%s\t%.2f\t%.2f\t%.2f\t%s\n",
        st[i].id,st[i].name,st[i].objective,st[i].subjective,st[i].sum,st[i].result);
    }
    fclose(fp);
}

 

运行结果截图

 

 

 

 

实验任务6

源代码

 

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

#define MAX_STU 80
typedef struct {
    char id[12];
    char name[20];
    char cls[30];
} Student;

int cmp(const void *a, const void *b) {
    Student *sa = (Student*)a;
    Student *sb = (Student*)b;
    return atoll(sa->id) - atoll(sb->id);
}

int main() {
    Student all_stu[MAX_STU];
    int flag[MAX_STU] = {0}; 

    Student lucky[5];
    int total_cnt = 0;
    srand((unsigned int)time(NULL)); 

    FILE *fin = fopen("list.txt", "r");
    if (!fin) {
        printf("无法打开学生名单文件list.txt\n");
        return 1;
    }
    while (fscanf(fin, "%s %s %s",
           all_stu[total_cnt].id,
           all_stu[total_cnt].name,
           all_stu[total_cnt].cls) != EOF) {
        total_cnt++;
        if (total_cnt >= MAX_STU) break;
    }
    fclose(fin);

    int cnt = 0;
    while (cnt < 5) {
        int idx = rand() % total_cnt;
        if (flag[idx] == 0) {
            flag[idx] = 1;
            lucky[cnt++] = all_stu[idx];
        }
    }

 

运行结果截图