实验7

task 4

#include <stdio.h>
#include <string.h>
#define N 80

int main(){
    int n;
    char ch[N];
    FILE *fp;
    
    fp=fopen("data4.txt", "r");
    if(fp==NULL){
        printf("fail to open file\n");
        return 1;
    }
    while(!feof(fp)){
        fscanf(fp, "%s", ch);
        n+=strlen(ch);
    }
    printf("data4.txt中共包含字符数（不计空白格）：%d", n);
    
    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");

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;
STU t;

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

task6

#include <stdio.h>
#include <time.h>
#define N 80
#define M 120

typedef struct {
char no[N];
char name[N];
char classroom[M];
} STU;

int main(){
    int i=0, k, flag[M]={0};
    STU x[M], t[5];
    FILE *fp, *ptr;
    fp=fopen("list.txt", "r");
    ptr=fopen("Lucky.txt", "w");
    
    if(fp==NULL)
    {
        printf("fail to open\n");
        return 1;
    }
    if(ptr==NULL)
    {
        printf("fail to open\n");
        return 1;
    }
    while(!feof(fp))
    {
        fscanf(fp,"%s%s%s",x[i].no, x[i].name, x[i].classroom);
        i++;
    }
    srand((unsigned)time(NULL));
    for(i=0;i<5;i++)
    {
        k=rand()%80;
        if(flag[k]==0)
            t[i]=x[k];
        flag[k]=1;
    }
    for(i=0;i<5;i++)
    {
        printf("%-30s%-30s%-30s\n",t[i].no, t[i].name, t[i].classroom);
        fprintf(ptr,"%-30s%-30s%-30s\n",t[i].no, t[i].name, t[i].classroom);
    }
    fclose(fp);
    fclose(ptr);
    
    return 0;
}