实验7

task 4

#include<stdio.h>

int main(){
    int count;
    char ch;
    FILE *fp;
    
    fp=fopen("data4.txt","r");
    if (fp==NULL){
        printf("fail to open file\n");
        return 1;
    }
    count=0;
    while(!feof(fp)){
        ch=fgetc(fp);
        if(ch==EOF)
            break;
        if(ch!=' '&&ch!='    '&&ch!='\n')
            count=count+1; 
        
    }
    
    printf("data4.txt中共包含字符数（不计空白符）：%d",count);
    fclose(fp);
    return 0;
}

task5

#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;          // 总分
    char ans[10];       // 考试结果
} STU;

// 函数声明
void finput(STU st[], int n);
void foutput(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);
    finput(stu, N);

    printf("\n对考生成绩进行统计...\n");
    cnt = process(stu, N, stu_pass);

    printf("\n通过考试的名单:\n");
    output(stu_pass, cnt);      // 输出到屏幕
    foutput(stu_pass, cnt);    // 输出到文件

    pass_rate = 1.0 * cnt / N;
    printf("\n本次等级考试通过率: %.2f%%\n", pass_rate*100);

    return 0;
}

// 把通过考试的考生完整信息输出到屏幕上
// 准考证号，姓名，客观题得分，操作题得分，总分，结果
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].ans);
}

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

    fclose(fin);
}

// 把通过考试的考生完整信息写入文件list_pass.txt
// 准考证号，姓名，客观题得分，操作题得分，总分，结果
void foutput(STU s[], int n) {
    FILE *fout;
    int i;
    
    // 保存到文件 
    fout = fopen("list_pass.txt", "w");
    if (!fout) {
        printf("fail to open or create list_pass.txt\n");
        exit(0);
    }
    
    fprintf(fout, "准考证号\t姓名           客观题得分               操作题得分    \t总分   \t\t结果\n");

    for (i = 0; i < n; i++)
        fprintf(fout, "%ld\t\t%-20s\t%.2f\t\t%.2f\t\t%.2f\t\t%-20s\n", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].ans);

    fclose(fout);
}

// 对考生信息进行处理：计算每位考生考试总分、结果；统计考试通过的人数
int process(STU st[], int n, STU st_pass[]) {
   int i,k;
   int count=0;
   for(i=0;i<n;++i){
       st[i].sum=st[i].objective+st[i].subjective;
       if(st[i].sum > 60){
           strcpy(st[i].ans,"pass");
           count =count +1;
       }
    else 
        strcpy(st[i].ans,"not pass");
   } 
   for(i=0,k=0;i<n;++i){
       if(strcmp(st[i].ans,"pass")==0){
           st_pass[k].id=st[i].id;
           strcpy(st_pass[k].name,st[i].name);
           st_pass[k].objective=st[i].objective;
           st_pass[k].subjective=st[i].subjective;
           st_pass[k].sum=st[i].sum;
           strcpy(st_pass[k].ans,st[i].ans);
           k++;
       }
       
   }
   return count;
}

task6

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

#define N 80 

typedef struct {
    long num;
    char name[20];
    char class[20];
}STU;

int main(){
    STU stu[N];
    int x[5];
    int i,j;
    int k,t=0;
    FILE *fp;
    FILE *ptr;
    
    fp=fopen("list.txt","r");
    if(fp==NULL){
        printf("fail to open \n");
        return 1; 
    }
    
    ptr=fopen("lucky.txt","w");
     if(ptr==NULL){
        printf("fail to open file\n");
        return 1; 
    }
    
    while(!feof(fp)){
        for(i=0;i<N;++i)
            fscanf(fp,"%ld %s %s",&stu[i].num ,stu[i].name ,stu[i].class );
    }
    fclose(fp);
    
    
    srand(time(NULL));
    k = rand() % N;
    x[0]=k;
    printf("%ld %-10s %-20s\n", stu[k].num, stu[k].name, stu[k].class);
    fprintf(ptr, "%ld %-10s %-20s\n", stu[k].num, stu[k].name, stu[k].class);
    
    for (i = 1; i < 5; ++i) {
        k = rand() % N;
        x[i]=k;
        for (j = 0; j < i; ++j) {
            if (x[i] == x[j]) {
                t=1;
            }
        } 
        if(t==0){
            printf("%ld %-10s %-20s\n", stu[k].num, stu[k].name, stu[k].class);
            fprintf(ptr, "%ld %-10s %-20s\n", stu[k].num, stu[k].name, stu[k].class);
        }
        if(t==1){
            i=i-1;
        }
    }


    fclose(ptr);
    
    return 0;
}