task4
//task4
#include<stdio.h>
int main()
{
int i = 0;
char ch;
FILE *fp;
fp = fopen("data4.txt", "r");
if(fp == NULL)
{
printf("读取失败\n");
return 1;
}
while(ch != EOF)
{
ch = fgetc(fp);
if(ch <= 126 && ch >= 33)
i++;
}
printf("data4.txt文件中字符数（不包括空白符):%d", i);
return 0;
}
结果
task5
源码
#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, k;
STU temp;
for(i = 0; i < n; i++)
s[i].sum = s[i].objective + s[i].subjective;
for(i = 0; i < n; i++)
{
k = i;
for(j = i + 1; j < n; j++)
if(s[k].sum < s[j].sum)
k = j;
temp = s[i];
s[i] = s[k];
s[k] = temp;
if(i == 0)
strcpy(s[i].level, "优秀");
if(i > 0 && i < 5)
strcpy(s[i].level, "合格");
if(i > 4)
strcpy(s[i].level, "不合格");
}
}
结果
task6
源码
//task6
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#define N 80
typedef struct
{
int id;
char name[20];
char classes[30];
} STU;
void input(STU s[], int n);
void output(STU s[], int n);
void process(STU s[], STU t[], int n);
int main()
{
STU stu[N], lucky[N];
int num;
printf("从文件读入学生信息\n\n");
input(stu, N);
srand(time(NULL));
while(1)
{
printf("请输入要抽取的学生人数：\n");
scanf("%d", &num);
if(num == 0)
break;
process(stu, lucky, num);
printf("\n抽取完毕，正在输出。\n\n");
output(lucky, num);
}
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, "%d %s %s", &s[i].id, s[i].name, s[i].classes);
}
fclose(fin);
}
void output(STU s[], int n)
{
FILE *fout;
int i;
time_t timeseed;
struct tm *now;
char name[N] = {0};
time(×eed);
now = localtime(×eed);
strftime(name, N, "%Y.%m.%d %H-%M-%S.txt", now);
printf("\n");
//printf("%s\n", name);
printf("学号\t\t姓名\t\t班级\n");
for (i = 0; i < n; i++)
printf("%d\t%s\t\t%s\n", s[i].id, s[i].name, s[i].classes);
printf("\n");
fout = fopen(name, "w");
if (!fout) {
printf("fail to open or create lucky.txt\n");
exit(0);
}
fprintf(fout, "学号\t\t姓名\t\t班级\n");
for (i = 0; i < n; i++)
fprintf(fout, "%d\t%s\t\t%s\n", s[i].id, s[i].name, s[i].classes);
fclose(fout);
}
void process(STU s[], STU t[], int n)
{
int i, k;
STU *temp[N];
for(i = 0; i < N; i++)
temp[i] = &s[i];
for( i = 0; i < n; )
{
k = rand()%N;
if(temp[k] != NULL)
{
t[i++] = s[k];
temp[k] = NULL;
}
}
}
结果
