实验6

task 4

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main() {
    FILE* fp;
    fp = fopen("D:\\.temp\\data4.txt", "r");
    if (feof(fp)) {
        printf("fail to open the file");
        return 1;
    }
    char ch;
    int n = 0;
    while ((ch = fgetc(fp))!= EOF) {
        if (ch != ' '&&ch!= '\n'&&ch!= '\t')
            n++;
    }
    fclose(fp);
    printf("data4.txt中共包含字符数（不计空白符）：%d", n);
    return 0;
}

 

 task 5

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

#define N 10
int k, a;

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

// 函数声明
void input(STU s[], int n);
void output(STU s[], int n);
void process(STU s[], int n);

int main() {
    STU stu[N];

    printf("从文件读入%d个考生信息: 准考证号，姓名，客观题得分(<=40)，操作题得分(<=60)\n", N);
    input(stu, N);

    printf("\n对考生信息进行处理: 计算总分，确定等级\n");
    process(stu, N);

    printf("\n打印考生完整信息, 并保存到文件中");
    output(stu, N);
    system("pause");

    return 0;
}

// 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 input(STU s[], 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", &s[i].id, s[i].name, &s[i].objective, &s[i].subjective);
    }

    fclose(fin);
}

// 输出考生完整信息: 准考证号，姓名，客观题得分，操作题得分，总分，等级
// 不仅输出到屏幕上，还写到文本文件result.txt中
void output(STU s[], int n) {
    FILE* fout;
    int i;

    // 输出到屏幕
    printf("\n");
    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等级\n");
    for (i = 0; i < n; i++)
        printf("%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].level);

    // 保存到文件 
    fout = fopen("result.txt", "w");
    if (!fout) {
        printf("fail to open or create result.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等级\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].level);

    fclose(fout);
}

// 对考生信息进行处理：计算总分，排序，确定等级
void process(STU s[], int n) {
    // 补足代码
    // ×××
    int i, j;
    STU m;
    for (i = 0; i < n; ++i) {
        s[i].sum = s[i].objective + s[i].subjective;
    }
    for (i = 0; i < n - 1; ++i) {
        for (j = n - 1; j > i; --j) {
            if (s[j].sum > s[j - 1].sum) {
                m = s[j];
                s[j] = s[j - 1];
                s[j - 1] = m;

            }
        }
    }
    
    k = n * 0.1;
    a = n * 0.5;
    for (i = 0; i < k; ++i)
        strcpy(s[i].level, "优秀");
    for (i = k; i < a; ++i)
        strcpy(s[i].level, "合格");
    for (i = a; i < n; ++i)
        strcpy(s[i].level, "不合格");

}

 

 task 6

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include<time.h>
typedef struct {
    long int no;
    char name[20];
    char grade[20];
} STU;

int main() {
    STU stu[80];
    int i, j;
    FILE* fin;

    fin = fopen("list.txt", "r");
    if (fin == NULL) {
        printf("fail to open file\n");
        exit(0);
    }
    while (!feof(fin)) {
        for (i = 0; i < 80; i++)
            fscanf(fin, "%ld %s %s", &stu[i].no, stu[i].name, stu[i].grade);
    }
    fclose(fin);

    FILE* fout;
    STU lucky[5];
    srand((unsigned int)time(NULL));
    for (i = 0; i < 5; i++)
    {
        lucky[i].no = 204942000 + (rand() % 80 + 1);
    }
    for (i = 0; i < 5; i++)
    {
        for (j = 0; j < 80; j++)
        {
            if (lucky[i].no == stu[j].no)
                lucky[i] = stu[j];
        }
    }
    for (i = 0; i < 5; i++)
        printf("%ld\t%s\t%s\n", lucky[i].no, lucky[i].name, lucky[i].grade);

    fout = fopen("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%s\t%s\n", lucky[i].no, lucky[i].name, lucky[i].grade);
    }
    fclose(fout);
    return 0;
}