任务4

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
int main() {
    char ch;
    int count = 0;
    FILE* fp;
    fp = fopen("D:\\data4.txt", "r");
    if (fp == NULL)
    {
         printf("fail to open file\n");
        return 1;
    }
    ch = fgetc(fp);
    while (ch != EOF)
    {
 
        if (ch != ' ' && ch != '\n')
            count++;
        ch = fgetc(fp);
    }
    printf("data4.txt中共包含字符数(不计空白符): %d\n", count);
    fclose(fp);
    system("pause");
    return 0;
}

任务5

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

#define N 10

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);

    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("D:\\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) {
     int i, j;
    STU t;
    for (i = 0; i < n; i++)
        s[i].sum = s[i].objective + s[i].subjective;

    for(i=0;i<n-1;i++)
        for(j=0;j<n-1-i;j++)
            if (s[j].sum < s[j + 1].sum)
            {
                t = s[j];
                s[j] = s[j + 1];
                s[j + 1] = t;
            }

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

任务6

#include<stdio.h>
#include<time.h>
#include<string.h>
#include<stdlib.h>
typedef struct {
    int num;
    char  name[20];
    char ban[20];
}STU;
int main(){
    FILE *fp,*fp1;
    STU s[80];
    fp1=fopen("D:\\lucky.txt","w");
    fp=fopen("D:\\list.txt","r");
    if(feof(fp)){
        printf("fail to open file");
        return 0;
    }
    int i;
    for(i=0;i<80;i++){
    fscanf(fp,"%d%s%s",&s[i].num,s[i].name,s[i].ban);
    }fclose(fp);
    srand((unsigned int)time(NULL));                 
    STU c[5];
    int j,t;
    for(i=0;i<5;i++){
    c[i].num=204942000+(rand()%80+1);
}     
    for(j=0;j<5;j++){
        for(t=0;t<80;t++){
            if(s[t].num==c[j].num)
            {  
            c[j]=s[t];
            }                           
        }
    }
    for(i=0;i<5;i++){
    printf("%d\t%s\t%s\n",c[i].num,c[i].name,c[i].ban);
    fprintf(fp1,"%d\t%s\t%s\n",c[i].num,c[i].name,c[i].ban);} 
    fclose(fp1); 
    return 0;
}