1. 编写程序用来要求用户录入国际电话区号，然后在数组country_codes中查找它（见16.3节）。如果找到对应的区号，程序需要显示相应的国家名称，否则显示出错消息。
#include#define ARRAY_LEN(x) ((int) (sizeof((x)) / sizeof((x)[0]))) const struct { char *country; int code; } country_codes[] = {{"Argentina", 54}, {"Bangladesh", 889}, {"Brazil", 55}, {"Burma (Myanmar)", 95}, {"China", 86}, {"Colombia", 57}, {"Congo, Dem. Rep. of", 243}, {"Egypt", 20}, {"Ethiopia", 251}, {"France", 33}, {"Germany", 49}, {"India", 91}, {"Indonesia", 62}, {"Iran", 98}, {"Italy", 39}, {"Japan", 81}, {"Mexico", 52}, {"Nigeria", 234}, {"Pakistan", 92}, {"Philippines", 63}, {"Poland", 48}, {"Russia", 7}, {"South Africa", 27}, {"South Korea", 82}, {"Spain", 34}, {"Sudan", 249}, {"Thailand", 66}, {"Turkey", 90}, {"Ukraine", 380}, {"United Kingdom", 44}, {"United States", 1}, {"Vietnam", 84}}; int main(void) { int code, i; printf("Enter an international dialing code: "); scanf("%d", &code); for (i = 0; i < ARRAY_LEN(country_codes); i++) { if (country_codes[i].code == code) { printf("%d is the code for %s.n", code, country_codes[i].country); return 0; } } printf("Error: %d is not a valid country code.n", code); return 0; }
2. 修改16.3节的inventory.c程序，使p（显示）操作可以按零件编号的顺序显示零件。
inventory.c
#include#include "inventory.h" #include "readline.h" #include "quicksort.h" int num_parts = 0; int find_part(int number); void insert(void); void search(void); void update(void); void print(void); int main(void) { char code; for (;;) { printf("Enter operation code: "); scanf(" %c", &code); while (getchar() != 'n') ; switch(code) { case 'i': insert(); break; case 's': search(); break; case 'u': update(); break; case 'p': print(); break; case 'q': return 0; default: printf("Illegal coden"); } printf("n"); } } int find_part(int number) { int i; for (i = 0; i < num_parts; i++) if (inventory[i].number == number) return i; return -1; } void insert(void) { int part_number; if (num_parts == MAX_PARTS) { printf("Database is full; can't add more parts.n"); return; } printf("Enter part number: "); scanf("%d", &part_number); if (find_part(part_number) >= 0) { printf("Part already exists.n"); return; } inventory[num_parts].number = part_number; printf("Enter part name: "); read_line(inventory[num_parts].name, NAME_LEN); printf("Enter quantity on hand: "); scanf("%d", &inventory[num_parts].on_hand); num_parts++; } void search(void) { int i, number; printf("Enter part number: "); scanf("%d", &number); i = find_part(number); if (i >= 0) { printf("Part name: %sn", inventory[i].name); printf("Quantity on hand: %dn", inventory[i].on_hand); } else printf("Part not found.n"); } void update(void) { int i, number, change; printf("Enter part number: "); scanf("%d", &number); i = find_part(number); if (i >= 0) { printf("Enter change in quantity on hand: "); scanf("%d", &change); inventory[i].on_hand += change; } else printf("Part not found.n"); } void print(void) { int i; quicksort(inventory, 0, num_parts-1); printf("Part Number Part Name " "Quantity on Handn"); for (i = 0; i < num_parts; i++) printf("%7d %-25s%11dn", inventory[i].number, inventory[i].name, inventory[i].on_hand); } inventory.h
#ifndef INVENTORY_H #define INVENTORY_H #define NAME_LEN 25 #define MAX_PARTS 100 struct part { int number; char name[NAME_LEN+1]; int on_hand; } inventory[MAX_PARTS]; #endifquicksort.c
#include "quicksort.h" void quicksort(struct part a[], int low, int high) { int middle; if (low >= high) return; middle = split(a, low, high); quicksort(a, low, middle - 1); quicksort(a, middle + 1, high); } int split(struct part a[], int low, int high) { struct part part_element = a[low]; for (;;) { while (low < high && part_element.number <= a[high].number) high--; if (low >= high) break; a[low++] = a[high]; while (low < high && a[low].number <= part_element.number) low++; if (low >= high) break; a[high--] = a[low]; } a[high] = part_element; return high; }quicksort.h
#ifndef QUICKSORT_H #define QUICKSORT_H #include "inventory.h" void quicksort(struct part a[], int low, int high); int split(struct part a[], int low, int high); #endifreadline.c
#include#include #include "readline.h" int read_line(char str[], int n) { int c, i = 0; while (isspace(c = getchar())) ; while (c != 'n' && c != EOF) { if (i < n) str[i++] = c; c = getchar(); } str[i] = ' '; return i; } readline.h
#ifndef READLINE_H #define READLINE_H int read_line(char str[], int n); #endif
3. 修改16.3节的inventory.c程序，使inventory和num_parts局部于main函数。
inventory.c
#includeinventory.h#include "inventory.h" #include "readline.h" #include "quicksort.h" int find_part(const struct part inventory[], int num_parts, int number); void insert(struct part inventory[], int *num_parts); void search(const struct part inventory[], int num_parts); void update(struct part inventory[], int num_parts); void print(struct part inventory[], int num_parts); int main(void) { int num_parts = 0; struct part inventory[MAX_PARTS]; char code; for (;;) { printf("Enter operation code: "); scanf(" %c", &code); while (getchar() != 'n') ; switch(code) { case 'i': insert(inventory, &num_parts); break; case 's': search(inventory, num_parts); break; case 'u': update(inventory, num_parts); break; case 'p': print(inventory, num_parts); break; case 'q': return 0; default: printf("Illegal coden"); } printf("n"); } } int find_part(const struct part inventory[], int num_parts, int number) { int i; for (i = 0; i < num_parts; i++) if (inventory[i].number == number) return i; return -1; } void insert(struct part inventory[], int *num_parts) { int part_number; if (*num_parts == MAX_PARTS) { printf("Database is full; can't add more parts.n"); return; } printf("Enter part number: "); scanf("%d", &part_number); if (find_part(inventory, *num_parts, part_number) >= 0) { printf("Part already exists.n"); return; } inventory[*num_parts].number = part_number; printf("Enter part name: "); read_line(inventory[*num_parts].name, NAME_LEN); printf("Enter quantity on hand: "); scanf("%d", &inventory[*num_parts].on_hand); (*num_parts)++; } void search(const struct part inventory[], int num_parts) { int i, number; printf("Enter part number: "); scanf("%d", &number); i = find_part(inventory, num_parts, number); if (i >= 0) { printf("Part name: %sn", inventory[i].name); printf("Quantity on hand: %dn", inventory[i].on_hand); } else printf("Part not found.n"); } void update(struct part inventory[], int num_parts) { int i, number, change; printf("Enter part number: "); scanf("%d", &number); i = find_part(inventory, num_parts, number); if (i >= 0) { printf("Enter change in quantity on hand: "); scanf("%d", &change); inventory[i].on_hand += change; } else printf("Part not found.n"); } void print(struct part inventory[], int num_parts) { int i; quicksort(inventory, 0, num_parts-1); printf("Part Number Part Name " "Quantity on Handn"); for (i = 0; i < num_parts; i++) printf("%7d %-25s%11dn", inventory[i].number, inventory[i].name, inventory[i].on_hand); } #ifndef INVENTORY_H #define INVENTORY_H #define NAME_LEN 25 #define MAX_PARTS 100 struct part { int number; char name[NAME_LEN+1]; int on_hand; }; #endif
4. 修改16.3节的inventory.c程序，为结构part添加成员price。insert函数应该要求用户录入新商品的价格。serach函数和print函数应该显示价格。添加一条新的命令，允许用户修改零件的价格。
#include#include "inventory.h" #include "readline.h" #include "quicksort.h" int find_part(const struct part inventory[], int num_parts, int number); void insert(struct part inventory[], int *num_parts); void search(const struct part inventory[], int num_parts); void update(struct part inventory[], int num_parts); void print(struct part inventory[], int num_parts); void change_price(struct part inventory[], int num_parts); int main(void) { int num_parts = 0; struct part inventory[MAX_PARTS]; char code; for (;;) { printf("Enter operation code: "); scanf(" %c", &code); while (getchar() != 'n') ; switch(code) { case 'i': insert(inventory, &num_parts); break; case 's': search(inventory, num_parts); break; case 'u': update(inventory, num_parts); break; case 'p': print(inventory, num_parts); break; case 'c': change_price(inventory, num_parts); break; case 'q': return 0; default: printf("Illegal coden"); } printf("n"); } } int find_part(const struct part inventory[], int num_parts, int number) { int i; for (i = 0; i < num_parts; i++) if (inventory[i].number == number) return i; return -1; } void insert(struct part inventory[], int *num_parts) { int part_number; if (*num_parts == MAX_PARTS) { printf("Database is full; can't add more parts.n"); return; } printf("Enter part number: "); scanf("%d", &part_number); if (find_part(inventory, *num_parts, part_number) >= 0) { printf("Part already exists.n"); return; } inventory[*num_parts].number = part_number; printf("Enter part name: "); read_line(inventory[*num_parts].name, NAME_LEN); printf("Enter quantity on hand: "); scanf("%d", &inventory[*num_parts].on_hand); printf("Enter price: "); scanf("%lf", &inventory[*num_parts].price); (*num_parts)++; } void search(const struct part inventory[], int num_parts) { int i, number; printf("Enter part number: "); scanf("%d", &number); i = find_part(inventory, num_parts, number); if (i >= 0) { printf("Part name: %sn", inventory[i].name); printf("Quantity on hand: %dn", inventory[i].on_hand); printf("Price: $%.2fn", inventory[i].price); } else printf("Part not found.n"); } void update(struct part inventory[], int num_parts) { int i, number, change; printf("Enter part number: "); scanf("%d", &number); i = find_part(inventory, num_parts, number); if (i >= 0) { printf("Enter change in quantity on hand: "); scanf("%d", &change); inventory[i].on_hand += change; } else printf("Part not found.n"); } void print(struct part inventory[], int num_parts) { int i; quicksort(inventory, 0, num_parts-1); printf("Part Number Part Name " "Quantity on Hand Pricen"); for (i = 0; i < num_parts; i++) printf("%7d %-25s%11d $%7.2fn", inventory[i].number, inventory[i].name, inventory[i].on_hand, inventory[i].price); } void change_price(struct part inventory[], int num_parts) { int i, number; printf("Enter part number: "); scanf("%d", &number); i = find_part(inventory, num_parts, number); if (i >= 0) { printf("Enter new price: "); scanf("%lf", &inventory[i].price); } else printf("Part not found.n"); }
5. 修改第5章的编程题8，以便用一个单独的数组存储时间。数组的元素都是结构，每个结构包含起飞时间和对应的抵达时间。（时间都是整数，表示从午夜开始的分钟数。）程序用一个循环从数组中搜索与用户输入的时间最接近的起飞时间。
#include#define ARRAY_LEN(x) (sizeof(x) / sizeof(x[0])) const struct flight { int departure; int arrival; } times[] = { {480, 616}, {583, 712}, { 679, 811}, {767, 900}, {840, 968}, {945, 1075}, {1140, 1280}, {1305, 1438} }; void print(const struct flight time); int main(void) { int user_time, hour, i, minute; printf("Enter a 24-hour time: "); scanf("%d :%d", &hour, &minute); user_time = hour * 60 + minute; printf("Closest departure time is "); for (i = 0; i < ARRAY_LEN(times) - 1; i++) { if (user_time <= times[i].departure + (times[i+1].departure - times[i].departure) / 2) { print(times[i]); return 0; } } i++; print(times[i]); return 0; } void print(const struct flight time) { printf("%d:%.2d %c.m., arriving at %d:%.2d %c.m.n", time.departure/60 > 12 ? time.departure/60 - 12 : time.departure/60, time.departure%60, time.departure > 719 ? 'p' : 'a', time.arrival/60 > 12 ? time.arrival/60 - 12 : time.arrival/60, time.arrival%60, time.arrival > 719 ? 'p' : 'a'); }
6. 修改第5章的编程题9，以便用户输入的日期都存储在一个date结构（见练习题5）中。把练习题5中的compare_dates函数集成到你的程序中。
#includestruct date { int year; int month; int day; }; int day_of_year(struct date d); int compare_dates(struct date d1, struct date d2); int main(void) { struct date d1, d2; int comparison; printf("Enter first date (mm/dd/yy): "); scanf("%d /%d /%d", &d1.month, &d1.day, &d1.year); printf("Enter second date (mm/dd/yy): "); scanf("%d /%d /%d", &d2.month, &d2.day, &d2.year); comparison = compare_dates(d1, d2); if (comparison > 0) printf("%d/%d/%d comes before %d/%d/%dn", d1.month, d1.day, d1.year, d2.month, d2.day, d2.year); else if (comparison < 0) printf("%d/%d/%d comes before %d/%d/%dn", d2.month, d2.day, d2.year, d1.month, d1.day, d1.year); else printf("%d/%d/%d and %d/%d/%d are equaln", d1.month, d1.day, d1.year, d2.month, d2.day, d2.year); return 0; } int day_of_year(struct date d) { int res = 0, i; const int days_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; if (d.month > 1 && ((d.year % 4 == 0 && d.year % 100 != 0) || d.year % 400 == 0)) res++; for (i = 0; i < d.month; i++) res += days_month[i]; return res + d.day; } int compare_dates(struct date d1, struct date d2) { int d1day = day_of_year(d1); int d2day = day_of_year(d2); if (d1day > d2day) return -1; else if (d1day < d2day) return 1; else return 0; }
