我正在为一所学校项目工作,我必须创建并将二叉树放入动态数组中。 我指定我使用GCC(GNU编译器)在Windows上工作。
typedef struct s_node * TN;
struct s_node {
char * chain; //Name of the tree
int occ; //Number of occurences
int ht; //Tree's height
};
typedef struct s_binary_tree * TBA;
struct s_binary_tree {
TN root;
TBA stl; //Sub Tree Left
TBA str; //Sub Tree Right
};
首先,我使用malloc()分配内存来创建一个包含x平方二叉树的数组,然后我为二叉树分配内存。
TBA create_Binary_Tree(char * chain, int occ, int number_letters) {
TBA tree = malloc(sizeof(TBA));
tree->root = malloc(sizeof(TN));
tree->root->chain = malloc(sizeof(char) * (number_letters + 1)); //+1 for the '\0'
*(tree->root->chain) = '\0';
strcpy(tree->root->chain,chain);
tree->root->occ = occ;
tree->root->ht = 1;
tree->stl = NULL;
tree->slr = NULL;
return tree;
}
TBA * create_Array_Binary_Tree(char * fileName) {
FILE * file;
file = fopen(fileName,"r");
if(!file) {
exit(EXIT_FAILURE);
}
int number_letters;
fscanf(file,"%d",&number_letters); //number_letters is the number of square that I want to allocate
TBA * arr = malloc(sizeof(TBA) * number_letters);
char * letter = malloc(sizeof(char) * 256);
int occ, i;
for(i = 0; i < number_letters; i++) { //number_letters = 1 in our example
fscanf(file,"%s %d",letter,&occ);
*arr = create_Binary_Tree(letter,occ,number_letters);
printf("--Adr = %p--\n"arr); //Print the adress
arr++;
}
arr -= i; //Reset the arr pointer
fclose(file);
return arr;
}
我的问题是当我计算数组的大小时,程序告诉我数组大小为x + 38平方。
int size_Array_Binary_Tree(TBA * arr) {
int sz_arr = 0;
while(*arr != NULL) {
printf("-T = %d\tAdr = %p-\n",sz_arr,arr); //Print the adress
sz_arr++;
arr++;
}
return sz_arr;
}
终端:
--Adr = 0000000000951430-- //1 square allocated
-T = 0 Adr = 0000000000951430- //The square allocated
-T = 1 Adr = 0000000000951438- //?
-T = 2 Adr = 0000000000951440- //?
-T = 3 Adr = 0000000000951448- //...
-T = 4 Adr = 0000000000951450-
-T = 5 Adr = 0000000000951458-
-T = 6 Adr = 0000000000951460-
-T = 7 Adr = 0000000000951468-
-T = 8 Adr = 0000000000951470-
-T = 9 Adr = 0000000000951478-
-T = 10 Adr = 0000000000951480-
-T = 11 Adr = 0000000000951488-
-T = 12 Adr = 0000000000951490-
-T = 13 Adr = 0000000000951498-
-T = 14 Adr = 00000000009514A0-
-T = 15 Adr = 00000000009514A8-
-T = 16 Adr = 00000000009514B0-
-T = 17 Adr = 00000000009514B8-
-T = 18 Adr = 00000000009514C0-
-T = 19 Adr = 00000000009514C8-
-T = 20 Adr = 00000000009514D0-
-T = 21 Adr = 00000000009514D8-
-T = 22 Adr = 00000000009514E0-
-T = 23 Adr = 00000000009514E8-
-T = 24 Adr = 00000000009514F0-
-T = 25 Adr = 00000000009514F8-
-T = 26 Adr = 0000000000951500-
-T = 27 Adr = 0000000000951508-
-T = 28 Adr = 0000000000951510-
-T = 29 Adr = 0000000000951518-
-T = 30 Adr = 0000000000951520-
-T = 31 Adr = 0000000000951528-
-T = 32 Adr = 0000000000951530-
-T = 33 Adr = 0000000000951538-
-T = 34 Adr = 0000000000951540-
-T = 35 Adr = 0000000000951548-
-T = 36 Adr = 0000000000951550-
-T = 37 Adr = 0000000000951558-
-T = 38 Adr = 0000000000951560- //?
返回的大小应为1,但返回39。 你能帮我吗?
编辑:我从类型中删除了指针并调整了其余部分,但问题仍然存在。
typedef struct s_node TN;
struct s_node {
...
};
typedef struct s_binary_tree TBA;
struct s_binary_tree {
TN * root;
TBA * stl;
TBA * str;
};
TBA * create_Binary_tree(...) {
TBA * tree = malloc(sizeof(TBA));
tree->root = malloc(sizeof(TN));
...
return tree;
}
TBA ** create_Array_Binary_Tree(...) {
...
TBA ** arr = malloc(sizeof(TBA *) * number_letters);
...
for(i = 0; i < number_letters; i++) {
...
arr[i] = malloc(sizeof(TBA));
arr[i] = create_Binary_Tree(...);
...
}
...
return arr;
}
有什么想法吗?
答案 0 :(得分:1)
此程序中有几个错误:
TBA create_Binary_Tree(char * chain, int occ, int number_letters) {
TBA tree = malloc(sizeof(TBA));
...
}
TBA
是结构的指针。当您分配sizeof(TBA)
时,您要求分配与指针需要的内存一样多的内存,这只是4个字节(32位)或8个字节(64位)。您想为 struct 分配空间:
TBA tree = malloc(sizeof(struct s_binary_tree));
同样的问题:
tree->root = malloc(sizeof(TN));
应该是:
tree->root = malloc(sizeof(struct s_node));
只有TBA * arr = malloc(sizeof(TBA) * number_letters);
实际上是正确的。
使用第二个变量来存储原始指针或您想要修改的变量,而不是像arr -= i;
那样使用凌乱的指针算术。
您不是NULL终止arr
。分配后,可能会有垃圾。如果您依赖于作为哨兵的话,最好确保用NULL填充它:
memset(arr, 0, sizeof(TBA) * number_letters);
// Or use `calloc`, `bzero`, ...
这可能是您size_Array_Binary_Tree
给您一个奇怪结果的原因。