实验七

 task 4

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 5
#define M 80

int main(){
    int i,k=0;
    char ch;
    FILE *fp;
    fp=fopen("data4.txt","r");
    if(fp==NULL){
        printf("fail to open file\n");
        return 1;
    }
    while(EOF!=(ch=fgetc(fp))){
        if(ch!='\0'&&ch!='\t'&&ch!=' '){
            k++;
        }
    }
    fclose(fp);
    printf("data4.txt中共包含字符数(不计空白符): %d\n",k);
    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;    // 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 t;
    for(i=0;i<n;i++){
        s[i].sum=s[i].objective+s[i].subjective;
        for(j=0;j<n-1;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");
        }
        if(i<n*0.5&&i>=n*0.1){
            strcpy(s[i].level,"合格");
        }
        if(i>=n*0.5&&i<n){
            strcpy(s[i].level,"不合格");
        }}}

task 6

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 80
typedef struct{
    long int id;
    char name[80];
    char classname[80];
}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){
        srand(time(NULL));
        int b[5];
        int i=0;
        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 create 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);    }