实验七

task4

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>

int main()
{
    char ch;
    FILE* fp;
    int n = 0;

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

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

    printf("data4.txt中共包含的字符数：%d", n);

    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;
    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("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 temp;
   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;j++){
        if (s[j].sum<s[j+1].sum) {
            temp=s[j];
            s[j]=s[j+1];
            s[j+1]=temp;
        }
    }

for (i=0;i<n;i++)
{
    if (i+1<=n*0.1) strcpy(s[i].level,"优秀");
    else if (i+1>0.1*n&&i+1<=0.5*n) strcpy (s[i].level,"合格") ;
     else strcpy (s[i].level,"不合格");

    }
}

task6

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 80
int main()
{
    typedef struct {
    long int id;
    char name[20];
    char class[40];
} STU;
    STU s[N];
    FILE *fin;
    int i,n;

    fin = fopen("list.txt","r");
    if(fin == NULL)
        {
            printf("fail to open\n");
            exit(0);
        }

    while (!feof(fin))
    {
        for(i = 0;i < N;i++)
            fscanf(fin, "%ld %s %s", &s[i].id, s[i].name, s[i].class);
    }

    srand(time(NULL));
    int x[5];
    for(i = 0;i < 5;i++)
        x[i] = rand()% 80 + 1;

    for(i =0;i < 5;i++)
    {
        printf("%ld\t%s\t%s\n",s[x[i]].id,s[x[i]].name,s[x[i]].class);
    }

    FILE *fout;
    fout = fopen("lucky.txt", "w");
    if (!fout) {
        printf("fail to open or create result.txt\n");
        exit(0);
    }

    for (i = 0; i < 5; i++)
        fprintf(fout,"%ld\t%s\t%s\n",s[x[i]].id,s[x[i]].name,s[x[i]].class);

    fclose(fout);

    return 0;
}