第七次上机作业

task 4

#include<stdio.h>
int main()
{
    char s[100];
    FILE *fp;
    int i = 0,j,k = 0;
    char ch;
    fp = fopen("data4.txt","rb");

    if(fp == NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    ch = fgetc(fp);
    
    while(ch!=EOF)
    {
        s[i++] = ch;
        ch = fgetc(fp);
    }

    for(j = 0;j<i-1;j++)
        if(s[j]!=' ')
            k++;

    fclose(fp);
    printf("data4.txt中共包含字符数（不计空白符）：%d",k-1);
    return 0;
}

task 5

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

#define N 10

typedef struct {
    long int id;
    char name[20];
    float objective;
    float subjective;
    float sum;
    char level[10];
} STU;

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;
}

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);
}

void output(STU s[], int n) {
    FILE *fout;
    int i;
    
    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);
    
    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);
}

void process(STU s[], int n) 
{
    
    int i,j,m=0;
    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<N;i++)
    {
        if(i==0)
        strcpy(s[i].level ,"优秀");
        else if(i>0&&i<4)
        strcpy(s[i].level,"合格");
        else
        strcpy(s[i].level,"不合格");
    } 
}

task 6

#include <stdlib.h>
#include <stdio.h>
#include <time.h> 
#define N 80

typedef struct
{
    long int id;
    char name[N];
    char classname[N];
}STU;

void input (STU s[], int n);
void process (STU s[], int n);

int main()
{
    STU stu[N];
    input (stu, N);
    process (stu, N);
    
    return 0;
 } 
 
void input (STU s[], int n)
{
    int i;
    FILE *fin;
    fin = fopen("list.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 %s",&s[i].id,s[i].name,s[i].classname);
    }
    
    fclose (fin);
}

void process (STU s[], int n)
{
    int b[5];
    int i;
    srand(time(NULL));
    for (i = 0;i < 5; ++i)
        b[i] = rand()%80 + 1;
        
    for(i=0;i<5;i++)
        printf("%ld\t%s\t%s\n",s[b[i]].id,s[b[i]].name,s[b[i]].classname);
        
    FILE *fout;   
    fout = fopen("lucky.txt","w");
    if(!fout)
    {
        printf("fail to open or creat lucky.txt\n");
        exit (0);
    } 
    for(i=0;i<5;i++)
    fprintf(fout,"%ld\t%s\t%s\n",s[b[i]].id,s[b[i]].name,s[b[i]].classname);
    
    fclose(fout); 
}