实验任务五

task1_1

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
	char name[M]; // 书名
	char author[M]; // 作者
}Book;
int main()
{
	Book x[N] = { {"一九八四", "乔治.奥威尔"},
	              {"美丽新世界", "赫胥黎"},
				  {"昨日的世界", "斯蒂芬.茨威格"},
				  { "万历十五年", "黄仁宇" },
				  { "一只特立独行的猪", "王小波" }
		    };
	int i;
	FILE* fp;
	fp = fopen("data1.txt", "w");
	if (fp == NULL)
	{
		printf("fail to open file\n");
		return 1;
	}
	for (i = 0; i < N; ++i)
	{
		fprintf(fp, "%-20s %-20s\n", x[i].name, x[i].author);
		printf("%-20s %-20s\n", x[i].name, x[i].author);
	}
	fclose(fp);
	return 0;
}

task1_2

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#define N 5
#define M 80
typedef struct
{
	char name[M]; 
	char author[M]; 
}Book;
int main()
{
	Book x[N];
	int i;
	FILE* fp;
	fp = fopen("data1.txt", "r");
	if (fp == NULL)
	{
		printf("fail to open file\n");
		return 1;
	}
	for (i = 0; i < N; ++i)
	{
		fscanf(fp, "%s %s\n", x[i].name, x[i].author);
		printf("%-20s %-20s\n", x[i].name, x[i].author);
	}
	fclose(fp);
	return 0;
}

问题回答：
因为name和author已经是数组首地址，所以不用加地址符

task2_1

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
	char name[M]; 
	char author[M]; 
}Book;
int main()
{
	Book x[N] = { {"一九八四", "乔治.奥威尔"},
	{"美丽新世界", "赫胥黎"},
	{"昨日的世界", "斯蒂芬.茨威格"},
	{"万历十五年", "黄仁宇"},
	{"一只特立独行的猪", "王小波"}
		    };
	int i;
	FILE* fp;
	fp = fopen("data2.dat", "wb");
	if (fp == NULL)
	{
		printf("fail to open file\n");
		return 1;
	}
	fwrite(x, sizeof(Book), N, fp);
	fclose(fp);
	return 0;
}

问题回答：
1.生成了名为data2.dat的数据文件
2.内容并不直观可见

task2_2

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
	char name[M]; 
	char author[M]; 
}Book;
int main()
{
	Book x[N];
	int i;
	FILE* fp;
	fp = fopen("data2.dat", "rb");
	if (fp == NULL)
	{
		printf("fail to open file\n");
		return 1;
	}
	fread(x, sizeof(Book), N, fp);
	for (i = 0; i < N; ++i)
		printf("%-20s%-20s\n", x[i].name, x[i].author);
	fclose(fp);
	return 0;
}

task3_2

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int main()
{
	int i = 0;
	FILE* fp;
	char ch;
	fp = fopen("data3_1.txt", "r");
	if (fp == NULL)
	{
    	printf("fail to find file\n");
    	return 1;
	}

	while ((ch = fgetc(fp)) != EOF)
	{
    	if (ch != '\n' && ch != ' ' && ch != '\t')
        	i++;
	}

	printf("data3_1.txt中共包含字符数：%d", i);

	fclose(fp);

	return 0;
}

task5

#define _CRT_SECURE_NO_WARNINGS
#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(<= 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;
}
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)
{
	STU t;
	int i, j;

		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 - i - 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 + 1) <= n * 0.1)
			strcpy(s[i].level, "优秀");
		else if ((i + 1) > n * 0.1 && (i + 1) <= n * 0.5)
			strcpy(s[i].level, "合格");
		else
			strcpy(s[i].level, "不合格");
	}
}

task6

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 5
#define M 80
typedef struct
{
	char xuehao[20];
	char name[20];
	char classm[20];
}lucky;
int main()
{
	int i, j;
	lucky s[M];
	FILE* fin;
	FILE* fout;
	srand(time(0));
	fin = fopen("list.txt", "r");
	if (fin == NULL)
	{
    	printf("fail to open file\n");
    	return 1;
	}
	for (i = 0; i < M; i++)
	{
    	fscanf(fin, "%s %s %s\n", s[i].xuehao, s[i].name, s[i].classm);
	}

	fout = fopen("lucky.txt", "w");
	if (fout == NULL)
	{
    	printf("fail to open file\n");
    	return 1;
	}
	for (i = 0; i < N; i++)
	{
    	j = rand() % (80) + 1;
    	printf("%-20s %-20s %-20s\n", s[j].xuehao, s[j].name, s[j].classm);
    	fprintf(fout, "%-20s %-20s %-20s\n", s[j].xuehao, s[j].name, s[i].classm);
	}
	fclose(fin);
	fclose(fout);
	system("pause");
}