在C结构的初始化变量矩阵 [英] Initializing an variable matrix in a structure C
问题描述
我有在C.结构初始化变量矩阵麻烦一直在读一对夫妇的职位(的帖子),但我似乎无法修复它。不要问我为什么但是对于一个任务,我需要初始化位于结构的矩阵。
我的code的结构是:
typedef结构迷宫{
INT行;
INT列;
焦炭矩阵[行] [列];
}迷宫;
通过调用不同的功能,读取某个文件后,我需要通过其给定参数初始化一个矩阵,所以2个参数行和列。
我的code的初始化函数是:
结构的迷宫* init_maze(INT行,诠释列){ 结构迷宫mazeFilled;
结构迷宫* mazePointer; mazeFilled.row =排;
mazeFilled.column =列; 返回mazePointer;
}
但你能猜到这是行不通的,人们已经提到,这是很难从2个变量创建一个矩阵。谁能解释一下我做错了。
编辑1:
我按照然而,结构仍然是相同的职位改变了我的code。我需要分配指针,所以它即使是外舀保持活跃。
我的新code为init FUNCT是:
结构的迷宫* init_maze(无效){ INT排= 6;
INT列= 10;
结构迷宫* mazePointer =的malloc(sizeof的(* mazePointer)); mazePointer->排排=;
mazePointer->列=列; 返回mazePointer;
}
编辑2:
我想我discoverd什么我的错误是,我没有为矩阵分配内存。
我的新初始化函数:
结构的迷宫* init_maze(无效){INT排= 6;
INT列= 10;迷宫* mazePointer;
mazePointer =的malloc(sizeof的(迷宫));
mazePointer->排排=;
mazePointer->列=列;
mazePointer->矩阵=的malloc(行*的sizeof(字符*));对于(INT I,I<排;我++){
对于(INT焦耳; J<列; J ++){
mazePointer - >矩阵[I] [J] =的malloc(1 * sizeof的(字符*));
}
}返回mazePointer;}
我仍然不知道如何分配的内存只是第一阵列,[1]。谁能告诉我,如果我在正确的方向?
谁能解释一下我做错了什么?
块引用>您正在返回一个指针到本地/自动存储时间结构是不能保证存在超出范围
{}
的功能。有许多方法可以做到这一点。这样做的目的是,即使在函数返回后,返回它仍然活着,活跃的结构。
较常用的方式做,这是动态分配的结构,填充它,然后返回一个指向它。
结构的迷宫* init_maze(INT行,诠释列)
{ 结构迷宫* pmazeFilled =的malloc(sizeof的(* pmazeFilled)); pmazeFilled->排排=;
pmazeFilled - >列=列; 返回pmazeFilled;
}记住调用者必须通过调用
免费
上返回的指针释放分配的内存。I am having trouble with initializing a variable matrix in a structure in C. Have been reading a couple of posts(post) but I cant seem to fix it. Don't ask me why but for an assignment I need to initialize a matrix located in a structure.
My code for the struct is:
typedef struct maze{ int row; int column; char matrix[row][column]; }maze;
By calling a different function, after reading a certain file, I need to initialize a matrix by its given parameters, so 2 parameters "row" and "column".
My code for the init function is:
struct maze* init_maze(int row, int column) { struct maze mazeFilled; struct maze *mazePointer; mazeFilled.row = row; mazeFilled.column = column; return mazePointer; }
But as you can guess this is not working, people already mentioned that it is hard to create a matrix from 2 variables. Could anyone explain what I am doing wrong.
EDIT 1:
I changed my code according to the posts the struct however remains the same. I needed to allocate the pointer so it even stays active outside the scoop.
My new code for the init funct is:
struct maze* init_maze(void) { int row = 6; int column = 10; struct maze *mazePointer = malloc(sizeof (*mazePointer)); mazePointer->row = row; mazePointer->column = column; return mazePointer; }
EDIT 2:
Think I discoverd what my error was, I did not allocate memory for the matrix. My new init function:
struct maze* init_maze(void) { int row = 6; int column = 10; maze *mazePointer; mazePointer = malloc(sizeof(maze)); mazePointer->row = row; mazePointer->column = column; mazePointer->matrix = malloc(row * sizeof(char*)); for (int i; i < row; i++) { for(int j; j < column; j++) { mazePointer -> matrix[i][j] = malloc(1 * sizeof(char*)); } } return mazePointer; }
I am still not sure how to allocate the memory for just the first array, [i]. Could anyone tell me if I am in the right direction?
解决方案Could anyone explain what I am doing wrong?
You are returning a pointer to a local/automatic storage duration structure which is not guaranteed to exist beyond the scope
{ }
of the function.
There are a number of ways to do this. The aim is return a structure which remains alive and active even after returning from the function.
The more commonly used way to do this is to allocate the structure dynamically, populate it and return a pointer to it.
struct maze* init_maze(int row, int column) { struct maze *pmazeFilled = malloc(sizeof(*pmazeFilled)); pmazeFilled->row = row; pmazeFilled ->column = column; return pmazeFilled; }
Remember the caller must free the allocated memory by calling
free
on the returned pointer.这篇关于在C结构的初始化变量矩阵的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!