实验七

task 4

源代码：

#include<stdio.h>

int main(){
    FILE *fp;
    fp = fopen("C:\\Users\\jr787\\Desktop\\实验7数据文件及部分代码_gbk\\data4.txt","r");
    if(fp == NULL){
        printf("fail to open file to write\n");
        return;
    }
    
    int row = 0,total = 0;
    char ch;
    while((ch = fgetc(fp)) != EOF){
        if(ch != ' ' && ch != '\n' && ch != '\t')
            total++;
        if(ch == '\n')
            row++;
    }
    row++;
    fclose(fp);
    printf("data4.txt统计结果：\n");
    printf("行数：%d\n",row);
    printf("字符数（不计空白符）：%d\n",total);
    return 0;
}

运行结果：

task 5

源代码：

#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("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);
}

void write(STU st[],int n){
    FILE *fp;
    fp = fopen("list_past.txt","w");
    if(fp == NULL){
       perror("fail to open to write\n");
       return;
   }
   
    int i;
    for(i = 0;i < n;++i){
        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);
}

int process(STU st[],int n,STU stpass[]){
    int cnt=0,i;
    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");
            stpass[cnt++]=st[i];
       }
       else
       strcpy(st[i].result,"未通过");
   }
   return cnt;
}

运行结果：

task 6

源代码：

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<string.h>
#define N 90
#define M 5

int main(){
    char s[N][N];
    char filename[80];
    char hit[N][N];
    FILE *fp,*fout;
    int has_hit[N] = {0};
    int i,n;
    int lucky_i;
    
    fp = fopen("C:\\Users\\jr787\\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(i < N && (fgets(s[i],N,fp)!= NULL)){
        printf("%s",s[i]);
        ++i; 
    }
    n = i;
    
    printf("\n------------中奖名单------------\n");
    srand(time(0));
    
    for(i = 0;i < M;i++){
        lucky_i = rand () % N ;
        
        if(has_hit[lucky_i])
            continue;
        
        has_hit[lucky_i] = 1;
        strcpy(hit[i],s[lucky_i]);
        printf("%s",s[lucky_i]);
    }
    
    printf("\n------------保存到文件------------\n");
    printf("输入文件名：") ;
    gets(filename);
    fout = fopen(filename,"w");
    if(!fout){
        perror(filename);
        return 1;
    }
    
    for(i =0;i < M;++i)
        fprintf(fout,"%s\n",hit[i]);
    
    printf("保存成功！");
    
    fclose(fout);
    fclose(fp);
    return 0; 

}

运行结果：