实验6

task4

#include<stdio.h>
#include<stdlib.h>
int main(){
FILE *fp;
int count=0;
fp=fopen("data4.txt","r");
if(fp==NULL){
printf("fail to open the file");
return 1;
}
char ch;
while((ch=fgetc(fp))!=EOF){
if(ch!=' '&&ch!='\n'&&ch!='\t')
count++;
}
fclose(fp);
printf("data4.txt中共包含字符数（不计空白符）：%d",count);
return 0;
}

task5

    int i,j;
    STU t;
    for(i=0;i<n;i++)
    s[i].sum=s[i].objective+s[i].subjective;
    for(j=0;j<n;j++)
    for(i=0;i<n-j-1;i++)
    {
        if(s[i].sum<s[i+1].sum)
        {
            t=s[i+1];
            s[i+1]=s[i];
            s[i]=t;
        }
    }
    for(i=0;i<n;i++)
    {
        if(i<0.1*(n-1))
        strcpy(s[i].level,"优秀");
        if(i>=0.1*(n-1)&&i<0.5*(n-1))
        strcpy(s[i].level,"合格");
        if(i>=0.5*(n-1))
        strcpy(s[i].level,"不合格");
    }

task6

//task 6#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h> 
#include <stdlib.h> 
#include <time.h>
#include <string.h>

 typedef struct 
 {
 long int no;
 char name[20];
 char clas[100];
} STU;


int main()
{
    int i,j;
    STU x[80];
    STU lucky[5];
    FILE *fp;
    fp = fopen("D://list.txt", "r");
    
    if(fp == NULL) 
    {
    printf("fail to open file\n");
    return 1;
    }
    
    while(!feof(fp))
    {
    for (i = 0; i < 80; i++)
    fscanf(fp, "%ld%s%s", &x[i].no,x[i].name, x[i].clas);
    }
    fclose(fp);
    
    FILE *fp2;
    
    fp2 = fopen("D://lucky.txt", "w");
    if(fp2 == NULL) 
    {
    printf("fail to open file\n");
    return 1;
    }
    
    srand ( time ( NULL ) ) ;  
    for(i=0;i<5;i++)
    lucky[i].no=204942000+rand()%80+1;
    
    for (i = 0; i < 5; i++)
    {
        for (j = 0; j < 80; j++)
        {
            if (lucky[i].no == x[j].no)
                lucky[i] = x[j];
        }
    }
    
    for(i = 0; i < 5; ++i)
    {
    fprintf(fp2,"%ld\t%s\t%s\n", lucky[i].no, lucky[i].name,lucky[i].clas);
    printf("%ld\t%s\t%s\n", lucky[i].no, lucky[i].name,lucky[i].clas);
    }
    
    fclose(fp2);
    
    return 0;
}