实验七

实验任务4

程序代码：

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

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

    fp=fopen("D:\\private\\learning\\data\\data4.txt","r");
    if(fp==NULL){
        printf("fail to open file");

        system("pause");
        return 1;
    }

    ch=fgetc(fp);
    while(ch!=EOF){
        if(ch!=' '&&ch!='\n')
            i++;
        ch=fgetc(fp);
    }
    printf("data4.txt中共包含字符数（不计空白符）：%d",i);
    system("pause");
    return 0;
}

运行结果：

实验任务5

程序代码：

#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("从文件中读入%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);

system("pause");
return 0;
}

void input(STU s[], int n) {
int i;
FILE *fin;
fin = fopen("D:\\private\\learning\\data\\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("D:\\private\\learning\\data\\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\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,k;
    float min;
    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,k=0,min=s[0].sum;j<N-i-1;j++)
            if(min>s[j].sum){
                min=s[j].sum;
                k=j;
            }
            t=s[N-i-1];
            s[N-i-1]=s[k];
            s[k]=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");
        }
    }
}

运行结果：

 实验任务6

程序代码：

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

int main(){
    int i,j,k;
    typedef struct{
        long int num;
        char name[10];
        char clas[30];
    }STU;
    FILE *fp1,*fp2;
    STU x[80],h[80];

    printf("请输入抽取学生人数：");
    scanf("%d",&k);
    fp1=fopen("D:\\private\\learning\\data\\list.txt","r");
    if(fp1==NULL){
        printf("fail to open file");
        system("pause");
        return 1;
    }
     i=0;
    while(!feof(fp1)){
        fscanf(fp1,"%ld %s %s",&x[i].num,x[i].name,x[i].clas);
        i++;
    }
    srand(time(NULL));
    for(i=0;i<k;i++){
        j=rand()%80+1;
        h[i]=x[j];
    }

    fp2=fopen("D:\\private\\learning\\data\\lucky.txt","w");
    if(fp2==NULL){
        printf("fail to open file");
        system("pause");
        return 1;
    }

    for(i=0;i<k;i++){
    fprintf(fp2,"%ld %-20s %-20s\n",h[i].num,h[i].name,h[i].clas);
    printf("%ld %-20s %-20s\n",h[i].num,h[i].name,h[i].clas);
    }

    fclose(fp1);
    fclose(fp2);

    system("pause");
    return 0;
}

运行结果：