实验7

task 4

#include<stdio.h>
#define N 3

void write();

int main() {
    write();

    char ch;
    int i = 0, k = 0;
    FILE* fp;

    fp = fopen("data4.txt", "r");
    if (!fp) {
        printf("fail to open file to read\n");
        return;
    }
    while (!feof(fp)) {
        ch = fgetc(fp);
        if (ch == EOF)
            break;
        if (ch != ' ' && ch != '\n' )
            i++;
        if (ch == '\n')
            k++;
        
    }
    fclose(fp);

    printf("data4.txt统计结果：\n");
    printf("行数：%20d\n", k);
    printf("字符数（不计空白符）：%5d", i);

    return 0;
}

void write() {
    char* ptr[N] = { "0123456789-0123456789",
                     "nuist2025",
                     "cosmos galaxy" };
    int i;
    FILE* fp;

    fp = fopen("data4.txt", "w");
    if (!fp) {
        printf("fail to open file to write\n");
        return;
    }

    for (i = 0;i < N;++i) {
        fputs(ptr[i], fp);
        fputs("\n", fp);
    }
    fclose(fp);
}

 task 5

#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...");
    cnt = process(stu, N, stu_pass);
    
    printf("\n通过考试的名单：\n");
    output(stu, N);
    write(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].result);
}
void read(STU st[], int n) {
    int i;
    FILE* fin;
    fin = fopen("C:\\Users\\admin\\Downloads\\实验7数据文件及部分代码\\实验7数据文件及部分代码\\examinee.txt", "r");
    if (!fin) {
        printf("fail to open file\n");
        return;
    }
    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 write(STU st[], int n) {
    int i;
    FILE* fp;

    fp = fopen("list_pass.txt", "w");

    if (fp == NULL) {
        printf("fail to open file to write\n");
        return;
    }

    fprintf(fp,"%-20s%-20s%-20s%-20s%-20s%-20s\n", "准考证号", "姓名", "客观题得分", "操作题得分", "总分", "结果");
    for (i = 0;i < n;i++) {
        if (st[i].sum >= 60)
            fprintf(fp,"%-20ld%-20s%-20.2f%-20.2f%-20.2f%-20s\n", st[i].id,
                st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].result);
    }
    fclose(fp);
}

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

task 6

#include<stdio.h>
#include<stdlib.h>
#define N 80
typedef struct {
    long id;
    char name[20];
    char class[50];
}STU;

void read(STU x[], int n);
void random(STU x[], int n,STU choose[]);

int main() {
    STU x[N], choose[N];
    char a[20];
    int i;
    FILE* fp;

    read(x, N);

    printf("————随机抽点名单————\n");
    random(x, N,choose);

    printf("————保存到文件————\n");
    printf("输入文件名：");
    scanf("%s", a);

    fp = fopen(a, "w");
    if (!fp) {
        printf("fail to open file to write\n");
        return;
    }
    else
        printf("保存成功！");

    for (i = 0;i < 5;i++)
        fprintf(fp, "%-15ld %-10s %-10s\n", choose[i].id, choose[i].name, choose[i].class);

    fclose(fp);

    return 0;
}

void read(STU x[], int n) {
    int i;
    FILE* fp;

    fp = fopen("C:\\Users\\admin\\Downloads\\实验7数据文件及部分代码\\实验7数据文件及部分代码\\list.txt", "r");
    if (!fp) {
        printf("fail to open file\n");
        return;
    }

    while (!feof(fp)) {
        for (i = 0;i < n;i++)
            fscanf(fp, "%ld %s %s", &x[i].id, x[i].name, x[i].class);
    }

    fclose(fp);
}

void random(STU x[], int n, STU choose[]) {
    int k,i,cnt=0;

    for (i = 0;i < 5;i++) {
        k = rand() % (n - 1);
        if (x[k].id != 0) {
            printf("%-15ld %-10s %-10s\n", x[k].id, x[k].name, x[k].class);
            choose[cnt++] = x[k];
            x[k].id = 0;
        }
    }
}