实验7 文件应用编程

任务4

源代码 

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

int main() {
    FILE *fp;
    int line_cnt = 0;
    int char_cnt = 0;
    int ch;
    int last_ch = '\n';
    int has_content = 0;

    fp = fopen("data4.txt", "r");

    while ((ch = fgetc(fp)) != EOF) {
        has_content = 1;
        last_ch = ch;

        if (ch == '\n')
            line_cnt++;

        if (ch != ' ' && ch != '\n' && ch != '\t')
            char_cnt++;
    }

    if (has_content && last_ch != '\n')
        line_cnt++;

    fclose(fp);

    printf("data4.txt统计结果:\n");
    printf("行数:\t\t\t%d\n", line_cnt);
    printf("字符数(不计空白符):\t%d\n", char_cnt);
    system("pause");
    return 0;
}

 

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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) {
    FILE *fout;
    int i;
    fout = fopen("list_pass.txt", "w");
    if (fout == NULL) {
        printf("fail to open file to write\n");
        return;
    }
    fprintf(fout, "%-10s%-8s%-12s%-12s%-8s%-8s\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++) {
        fprintf(fout, "%-10ld%-8s%-12.2f%-15.2f%-10.2f%-8s\n",
                st[i].id, st[i].name, st[i].objective,
                st[i].subjective, st[i].sum, st[i].result);
    }
    fclose(fout);
}

 

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任务6

源代码 

 

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

#define N 100
#define WIN_NUM 5

typedef struct {
    char id[20];
    char name[50];
    char cls[100];
} Stu;

int readFile(Stu s[], char fn[]);
void lottery(int total, int win[]);
void printWin(Stu s[], int win[]);
void saveFile(Stu s[], int win[], char fn[]);

int main() {
    Stu s[N];
    int win[WIN_NUM];
    int total;
    char fn[50];

    total = readFile(s, "list.txt");

    lottery(total, win);
    printWin(s, win);

    printf("\n请输入保存文件名：");
    scanf("%s", fn);
    saveFile(s, win, fn);
    printf("保存成功！\n");
    system("pause");
    return 0;
}

int readFile(Stu s[], char fn[]) {
    FILE *fp;
    int n = 0;

    fp = fopen(fn, "r");
    while (fscanf(fp, "%s%s%s", s[n].id, s[n].name, s[n].cls) != EOF) {
        n++;
        if (n >= N) break;
    }
    fclose(fp);
    return n;
}

void lottery(int total, int win[]) {
    int flag[N] = {0};
    int i, idx;

    srand((unsigned)time(NULL));

    for (i = 0; i < WIN_NUM; ) {
        idx = rand() % total;
        if (flag[idx] == 0) {
            win[i] = idx;
            flag[idx] = 1;
            i++;
        }
    }
}

void printWin(Stu s[], int win[]) {
    int i;
    printf("\n------------ 中奖名单------------\n");
    for (i = 0; i < WIN_NUM; i++) {
        printf("%s\t%s\t%s\n", s[win[i]].id, s[win[i]].name, s[win[i]].cls);
    }
    printf("\n-----------保存到文件------------\n");
}

void saveFile(Stu s[], int win[], char fn[]) {
    FILE *fp;
    int i;

    fp = fopen(fn, "w");
    for (i = 0; i < WIN_NUM; i++) {
        fprintf(fp, "%s\t%10s\t%20s\n", s[win[i]].id, s[win[i]].name, s[win[i]].cls);
    }
    fclose(fp);
}

 

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实验总结

1.在任务4中，我用绝对路径和相对路径分别编写了一遍，在相对路径的编释中，未把data4.txt文件移动到项目的根目录（项目名.vcxproj)里，导致程序找不到相应文件。