实验七

实验4：

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#define N 500
int main() {
    FILE* fp;
    char ch;
    int s=0, m=0;
    fp = fopen("C:\\Users\\冯韬\\Desktop\\实验7数据文件及部分代码_gbk\\data4.txt","r");
    if (!fp)
        perror("data4.txt");
    while ((ch = fgetc(fp)) != EOF) {
        if (ch == '\n')
            s++;
        if (ch != ' ' && ch != '\n' && ch != '\t')
            m++;
    }
    s++;
    printf("data4.txt统计结果：\n");
    printf("行数：%-20d", s);
    printf("字符数（不计空白符）:%-20d", m);
    fclose(fp);
    return 0;
}

实验6：

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 90
#define M 5
int main() {
    FILE* fp;
    FILE* fout;
    char filename[80];
    int i, n;
    int lucky_i;
    int has_hit[N] = { 0 };
    char s[N][N];
    fp = fopen("C:\\Users\\冯韬\\Desktop\\实验7数据文件及部分代码_gbk\\list.txt", "r");
    if (!fp) {
        perror("list.txt");
        return 1;
    }
    i = 0;
    while (fgets(s[i], N, fp) != NULL)
        i++;
    n = i;
    srand(time(0));
    for (i = 0; i < M; ) {
        lucky_i = rand() % n;
        if (has_hit[lucky_i])
            continue;
        has_hit[lucky_i] = 1;
        printf("%s", s[lucky_i]);
        ++i;
        
    }
    printf("Enter filename:");
    gets(filename);
    fout = fopen(filename, "w");
    if (!fout) {
        perror(filename);
        return 1;
    }
    else
        printf("保存成功！");
    fclose(fp);
    fclose(fout);
    return 0;
}

实验5：

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.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...\n",N);
    read(stu, N);
    printf("\n对考生成绩进行统计...\n");
    cnt = process(stu, N, stu_pass);
    printf("\n通过考试名单：\n");
    output(stu, N);
    write(stu, N);
    pass_rate = 1.0 * cnt / N;
    printf("\n本次考试通过率：%.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].result);
}
void read(STU st[], int n) {
    int i;
    FILE* fin;

    fin = fopen("C:\\Users\\冯韬\\Downloads\\实验7数据文件及部分代码_gbk\\实验7数据文件及部分代码_gbk\\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;
    int k=0;
    for (i = 0; i < n; i++) {
        st[i].sum = st[i].subjective + st[i].objective;
        if (st[i].sum >= 60) {
            strcpy(st[i].result, "通过");
            st_pass[k++] = st[i];
        }
        else
            strcpy(st[i].result, "不通过");
    }
    return k;
}
void write(STU st[], int n) {
    FILE* fp;
    int i;
    fp = fopen("C:\\Users\\冯韬\\Downloads\\实验7数据文件及部分代码_gbk\\实验7数据文件及部分代码_gbk\\list_pass.txt", "w");
    if (!fp) {
        perror("list_pass.txt");
        return 1;
    }
    fprintf(fp,"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++) {
        if (st[i].sum >= 60)
            fprintf(fp, "%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);
    }
    fclose(fp);
}