实验7

任务4
源代码

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#include <stdio.h>
#include <ctype.h> 

int main() {
 
    FILE *fp;
    int line_count = 0;    
    int char_count = 0;   
    int ch;               

   
    fp = fopen("data4.txt", "r"); 
    if (fp == NULL) {
        perror("文件打开失败");  
        return 1;  
    }

    
    while ((ch = fgetc(fp)) != EOF) {
      
        if (ch == '\n') {
            line_count++;
        }

       
        
        if (!isspace(ch)) {
            char_count++;
        }
    }

  
    if (line_count > 0 || char_count > 0) {
        line_count++;
    }

  
    fclose(fp);

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

    return 0; 
}

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任务5
源代码

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#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);
}


 int i;
    FILE *fout;
    
    fout = fopen("list_pass.txt", "w");
    if (!fout) {
        printf("fail to open write file\n");
        return;
    }
    
    fprintf(fout, "准考证号\t姓名\t客观题得分\t操作题得分\t总分\t结果\n");
   
    for (i = 0; i < n; i++) {
       
        if (strcmp(s[i].result, "通过") == 0) {
            fprintf(fout, "%ld\t%s\t%.2f\t%.2f\t%.2f\t%s\n",
                    s[i].id, s[i].name, s[i].objective,
                    s[i].subjective, s[i].sum, s[i].result);
        }
    }
    fclose(fout);
}


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

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任务6
源代码

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

#define N 100  
#define LUCKY_NUM 5  

int main() {
    char s[N][N];  
    char hit[N][N];  
    int i, n=0, lucky_i;
    int has_hit[N] = {0};  
    FILE *fin, *fout;      
    char filename[50];     

   
    fin = fopen("list.txt", "r");
    if (!fin) {  
        perror("list.txt");
        return 1;
    }

   
    i = 0;
    while (fgets(s[i], N, fin) != NULL) { 
     
        s[i][strcspn(s[i], "\n")] = '\0';
        ++i;
    }
    n = i;  

  
    srand((unsigned int)time(NULL)); 
    for (i = 0; i < LUCKY_NUM; ) {    
        lucky_i = rand() % n;         
        if (has_hit[lucky_i] == 0) { 
            strcpy(hit[i], s[lucky_i]); 
            has_hit[lucky_i] = 1;      
            i++;
        }
    }

   
    printf("-----中奖名单-----\n");
    for (i = 0; i < LUCKY_NUM; i++) {
        printf("%s\n", hit[i]);
    }

  
    printf("enter filename: ");
    scanf("%s", filename);         
    fout = fopen(filename, "w"); 
    if (!fout) {                   
        perror("file open error");
        return 1;
    }
    for (i = 0; i < LUCKY_NUM; i++) {
        fprintf(fout, "%s\n", hit[i]);  
    }

 
    fclose(fin);
    fclose(fout);
    printf("保存成功！\n");

    return 0;
}

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