您好以下是我的代码，我需要在check_boundary函数中寻求帮助，因为我如何才能检索初始化的2d（就座）数组，以便可以将其与新的行和列号进行比较，目前我在该函数中获得0 0行和列如果我打印出来。座位数组在auditium_seating_init函数中实例化。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct guest {
char last_name[30];
char first_name[30];
};
struct auditorium_seating {
struct guest **seating;
};
void guest_init_default(struct guest *g)
{
strcpy_s(g->first_name,sizeof(g->first_name), "???");
strcpy_s(g->last_name, sizeof(g->last_name), "???");
}
void guest_init(struct guest *g, char *info)
{
char *token,*token1;
token1 = strtok_s(info, "/",&token);
strcpy_s(g->first_name,sizeof(g->first_name), token1);
token=strtok_s(NULL, "/", &token);
strcpy_s(g->last_name, sizeof(g->last_name), token);
}
void guest_to_string(struct guest *g)
{
printf("%c", g->first_name[0]);
printf(".%c", g->last_name[0]);
}
void auditorium_seating_init(int rowNum, int columnNum, struct auditorium_seating *a)
{
a->seating = malloc(rowNum * sizeof(a->seating));
for (int i = 0; i < rowNum; i++) {
a->seating[i] = malloc(columnNum * sizeof(**a->seating));
for (int j = 0; j < columnNum; j++) {
guest_init_default(&a->seating[i][j]);
}
}
}
int assign_guest_at(int row, int col, struct auditorium_seating *a, struct guest* g)
{
if ((strcmp(a->seating[row][col].first_name , "???") == 1 ) && (strcmp(a->seating[row][col].last_name, "???") == 1))
{
a->seating[row][col] = *g;
return 1;
}
else
{
return 0;
}
}
这个功能
int check_boundaries(int row, int col, struct auditorium_seating *a)
{
int total = sizeof(a->seating);
//printf("total %d", sizeof(a->seating));
//printf("col %d", sizeof(a->seating) / sizeof(a->seating[0]));
//printf("row %d", sizeof(a->seating[0]) / sizeof(a->seating[0][0]));
if (row >= 0 && col >= 0 && (col <= sizeof(a->seating[0])) && row <= (total / sizeof(a->seating[0]))) {
//printf("col %p",sizeof(a->seating[0]));
//printf("row %p", total/sizeof(a->seating[0]));
return 1;
}
else
{
return 0;
}
}
这是我的主要
void main() {
struct auditorium_seating auditorium_seating;
struct guest temp_guest;
int row, col, rowNum, columnNum;
char guest_info[30];
// Ask a user to enter a number of rows for an auditorium seating
printf("Please enter a number of rows for an auditorium seating.");
scanf_s("%d", &rowNum);
// Ask a user to enter a number of columns for an auditorium seating
printf("Please enter a number of columns for an auditorium seating.");
scanf_s("%d", &columnNum);
/*** reading a guest's information ***/
// auditorium_seating
//scanf_s("%c", guest_info);
auditorium_seating_init(rowNum, columnNum, &auditorium_seating);
printf("Please enter a guest information or enter \"Q\" to quit.");
/*** reading a guest's information ***/
scanf_s("%s", guest_info, sizeof(guest_info));
//scanf("%s", guest_info);
/* we will read line by line **/
while ( strcmp(guest_info,"Q")==1) {
printf("\nA guest information is read.");
// printing information.
printf("%s", guest_info);
// guest
guest_init(&temp_guest, &guest_info);
// Ask a user to decide where to seat a guest by asking
// for row and column of a seat
printf("Please enter a row number where the guest wants to sit.");
scanf_s("%d", &row);
printf("Please enter a column number where the guest wants to sit.");
scanf_s("%d", &col);
// Checking if the row number and column number are valid
// (exist in the theatre that we created.)
if (check_boundaries(row, col, &auditorium_seating) == 0) {
printf("\nrow or column number is not valid.");
printf("A guest %s %s is not assigned a seat.", temp_guest.first_name, temp_guest.last_name);
}
else {
// Assigning a seat for a guest
if (assign_guest_at(row, col, &auditorium_seating, &temp_guest) == 1) {
printf("\nThe seat at row %d and column %d is assigned to the guest", row, col);
guest_to_string(&temp_guest);
auditorium_seating_to_string(&auditorium_seating);
}
else {
printf("\nThe seat at row %d and column %d is taken.", row, col);
}
}
// Read the next guestInfo
printf("Please enter a guest information or enter \"Q\" to quit.");
/*** reading a guest's information ***/
scanf_s("%s", guest_info, sizeof(guest_info));
}
}
最佳答案
您似乎遇到的大量问题通常反映出一定比例的不读书的人口。我只是把它放在那儿，似乎您是其中的一员，对我们许多人来说都很明显。您想看起来像其中一个人吗？
希望你能证明我是错的，因为那些人甚至不应该在这里问他们是否不愿意阅读...
int total = sizeof(a->seating);
这到底是什么？好的，首先，
sizeof表达式是size_t类型，而不是int类型。当您不想编写负处理代码（例如check_boundaries）时，这很有意义。这样可以节省那些花很多时间在读书上的人。您需要修改您的
struct auditorium_seating（目前仅是误导的typedef）来存储该信息，因为sizeof运算符在编译时而不是在运行时完成其大部分工作，因此它无法检索malloc返回的对象的大小。您似乎对此感到两难，所以请允许我开始：
struct auditorium_seating {
size_t row_size, column_size; // and along with this comes more code throughout your project
struct guest **seating;
};
int check_boundaries(size_t row, size_t column, struct auditorium_seatching *a) {
return (row < a->row_size && column < a->column_size);
}
修改
seating（即初始化或“向其中添加元素”）时，可能还需要修改row_size或column_size。继续对您的代码进行这些更改。就这些。void main()
在C中，应始终（几乎）声明
main以返回int。如果不是，您应该知道为什么不是。在这种情况下，没有证据表明您确实知道为什么选择void，应该在哪里。只需在此处使用
int，然后...注意此警告：当您执行错误操作时，C并不是那种会通过错误消息来惩罚您的语言。在安全漏洞面前，错误常常被忽视很多年，而令人流血的例子就是其中之一。请，如果您还没有这样做的话，请让我们免于再次伤心，并让自己读书。
/* we will read line by line **/
扰流板警报！这不是the manual所说的！
“
s匹配不是空格字符的字节序列。”如果您错过了这么小的细节，也不会令我感到惊讶，因为那些不愿读书的人也更喜欢不读书。如果您是其中的一员，则不应成为程序员。采摘水果。
printf("\nA guest information is read.");
我们将
'\n'放在最后是有原因的。当然，您需要阅读以找到该原因。嘿，您正在阅读此答案！为什么不读一本书，它可以告诉您所有这些事情（以及更多）？'\n'在写入行缓冲流中时会导致隐式fflush。因此，如果要确保输出立即显示在终端上，则需要将'\n'放在末尾，或者在fflush(stdout);之后调用printf。我宁愿选择那些不太可怕的选择。关于c - 在C中访问2d数组，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/46315630/