C primer plus 编程练习 14.18

//CPP 14.18-1
#include <stdio.h>
#include <string.h>
char * s_gets(char *st,int n);
int days(const char ar[]);
typedef struct 
{
	char name[10];
	int days;
}month;
month months[12] = 
{
	{"January",31},
	{"February",28},
	{"March",31},
	{"April",30},
	{"May",31},
    {"June",30},
	{"July",31},
	{"August",31},
	{"september",30},
	{"October",30},
	{"Novemember",30},
	{"December",31}
};
int main(void)
{
	char input[10];
	int total;
	printf("请输入您要计算的月份名：");
	while (s_gets(input,10) != NULL && input[0] != '\n')
	{
		printf("您输入的月份是: %s\n",input);
		total = days(input);
		if (total != -1)
		    printf("计算结果为：%d 天\n",total);
        else 
			printf("您输入的月份名称不存在！\n");
		printf("请输入下一个您要计算的月份名：");
	}
    printf("再见！\n");
    
	return 0;
}
int days(const char ar[])
{
	int index,total;
	for (index = 0;index < 12 ; index++)
	{
		if (strcmp(months[index].name,ar) == 0)
		    break;
	}
	if (index == 12)
	    return -1;
	else
	{
		int i = 0;
		for (i = 0,total = 0;i < index ;i++ )
		    total += months[i].days;
	}
	return total;
}
char * s_gets(char *st,int n)
{
	char * ret_val;
	char * find;
	ret_val = fgets(st,n,stdin);
	if (ret_val)
	{
		find = strchr(st,'\n');
		if (find)
		    *find = '\0';
		else
			while (getchar() != '\n')
			    continue;
	}
	return ret_val;
}

//CPP 14.18-8
#include <stdio.h>
#include <stdlib.h>
#define LEN 20
typedef struct _planestats {
	int seat_id;
	int status;
	char last[LEN];
	char first[LEN];
}Planestats;
char getmenu();
void show_empties(const Planestats seat [], int n);
void show_orderlist(const Planestats list [],int n);
void order_seat(Planestats ptro [],Planestats ptrp [], int * p_ct);
void order_del(Planestats ptro [],Planestats ptrp [], int * p_ct);
int main(void)
{
	char choice; 
	int ct_order = 0; //记录用户已经定的座位数
	int ct_empty; //记录剩余座位数
    Planestats planeseat[12] = {{1,0,'\0','\0'},{2,0,'\0','\0'},{3,0,'\0','\0'},
		{4,0,'\0','\0'},{5,0,'\0','\0'},{6,0,'\0','\0'},{7,0,'\0','\0'},{8,0,'\0','\0'},
		{9,0,'\0','\0'},{10,0,'\0','\0'},{11,0,'\0','\0'},{12,0,'\0','\0'}};   //初始化座位信息
	Planestats orderlist[12] =  {{1,0,'\0','\0'},{2,0,'\0','\0'},{3,0,'\0','\0'},
		{4,0,'\0','\0'},{5,0,'\0','\0'},{6,0,'\0','\0'},{7,0,'\0','\0'},{8,0,'\0','\0'},
		{9,0,'\0','\0'},{10,0,'\0','\0'},{11,0,'\0','\0'},{12,0,'\0','\0'}};   //初始化座位信息
	choice = getmenu();
	while (choice != 'e')
	{
		switch (choice)
		{
		case 'a':  //显示剩余座位信息
            show_empties(planeseat,12);
			break;
		case 'b':  //显示您当前预定座位的信息
            show_orderlist(orderlist,ct_order);
			break;
		case 'c':  //预定一个座位
		    order_seat(orderlist,planeseat,&ct_order);
			break;
		case 'd':  //删除一个预定的座位
		    order_del(orderlist,planeseat,&ct_order);
			break;
		}
		choice = getmenu();
	}
    printf("再见!\n");
    
	return 0;
}
void order_del(Planestats ptro [],Planestats ptrp [], int * p_ct)
{
	int id;
	printf("请选择您要删除的座位编号：\n");
	while (scanf("%d",&id) == 1 && (id > 0 && id < 12))
	{
        fflush(stdin);
        if (ptrp[id - 1].status == 1)
		{
			(*p_ct)--;
			ptrp[id - 1].status = 0;
			ptro[id - 1].status = 0;
			break;
		}
		else
			printf("您未预定该座位，请重新选择已经预定的座位编号.\n");
	}

}
void order_seat(Planestats ptro [],Planestats ptrp [], int * p_ct)
{
	int id;
	printf("请输入您要预定的座位编号：\n");
	while (scanf("%d",&id) == 1 && (id >= 1 && id <= 12))
	{
		fflush(stdin);
		if (ptrp[id - 1].status == 0)
		{
			(*p_ct)++;
			ptrp[id - 1].status = 1;
			ptro[id - 1].status = 1;
			printf("请输入预订人的姓氏：\n");
			scanf("%s",&ptro[id - 1].first);
			printf("请输入预订人的名：\n");
			scanf("%s",&ptro[id - 1].last);
			break;
		}
		else
			printf("该座位已经被预定，请预定其他座位.\n");
	}
}
void show_orderlist(const Planestats list [],int n)
{
	int index;
	if (n == 0)
	    printf("您当前还没有预定座位！\n");
	else
	{
		printf("您已经预定的座位信息：\n");
		printf(" 座位编号 预订人姓名\n");
		for (index = 0;index < 12 ;index++ )
			if (list[index].status == 1)
		        printf(" %-8d %s%s\n",list[index].seat_id,list[index].first,list[index].last);
	}
}
void show_empties(const Planestats seat [], int n)
{
	int index;
	int count = 0;
	printf(" 未被预定的座位编号:\n");
	for (index = 0;index < n; index++ )
	{
		if (seat[index].status == 0)
		{
			count++;
		    printf(" %d\t",seat[index].seat_id);
		}
	}
	putchar('\n');
	printf("当前一共剩余空座位数量为 %d\n",count);
}
char getmenu()
{
	char choice;
	puts("*************************************");
	puts("请选择一个功能（输入对应的字母标签）：");
	puts("a).显示剩余座位信息");
	puts("b).显示您当前预定座位的信息");
	puts("c).预定一个座位");
	puts("d).删除一个预定的座位");
	puts("e).退出");
	puts("*************************************");
	choice = getchar();
	while (choice < 'a' || choice > 'e')
	{
		printf("请输入a,b,c,d,e中的一个: \n");
	    fflush(stdin);
        choice = getchar();
	}
	fflush(stdin);
	return choice;
}