我必须将一个结构数组的元素复制到新结构数组的空白元素（全部动态分配）。我所拥有的结构数组的每个元素（结构'a'）只有两列，left_column和right_column。结构a的每个元素的一些右列条目（例如，我的结构元素）匹配相同结构的下一个（即，第i + 1个）结构元素的左列条目{{ 1}}。我试图找到这样的匹配条目，我试图将匹配元素的整个左右列一个一个地复制到一个较小的，保守的结构，结构a。问题是代码正在编译，但它没有进入最重要的匹配部分，即b部分。它正在进入if循环。
以下是信息和样本数据。由于'PlerumCodeExperientia'，这段代码已经到了这个阶段，我感谢他。请建议如何复制这些匹配元素。
感谢你，Dan。
while文件看起来： 第一个结构元素的片段如下所示：
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char* args[])
{
struct a
{
int left_line;
int right_line;
};
struct b
{
int conserved_left;
int conserved_right;
};
FILE *fp100; // Output File
fp100 = fopen("Conserved_Elements.txt", "a");
struct a *ptr1;
int structACapacity = 3; // Only 3 such comparison files are being worked with, there are >1000 comparison files
ptr1 = malloc(structACapacity*sizeof(struct a));
struct b *ptr2;
int structBCapacity = 1000;
ptr2 = malloc(structBCapacity*sizeof(struct b));
int structure_ctr;
int number_of_line_comparison_files = 3; // Only 3 for the time being
int knt;
int left, right;
for (structure_ctr=0; structure_ctr < number_of_line_comparison_files; structure_ctr++) {
knt = 0;
while (((ptr1+knt) < (ptr1+structACapacity-1)) && (knt < 500)) {
fprintf(fp100, "Getting Into While\n");
// finding the matching entries between right column of knt and left column of (knt+1)
if ((ptr1+knt)->right_line == (ptr1+(1+knt))->left_line) {
fprintf(fp100,"\tGetting Into the If\n");
// copying matching values to the struct b
left = (ptr2+knt)->conserved_left = (ptr1+knt)->left_line;
right = (ptr2+knt)->conserved_right = (ptr1+knt)->right_line;
//fprintf(fp100,"C-Left:%d\tC-Right:%d\tLeft%d\tRight%d\n",(ptr2+knt)->conserved_left,(ptr2+knt)->conserved_right,left,right);
// left, right are there for convinience only - easier to see, same values
fprintf(fp100,"C-Left:%d\tC-Right:%d\n", left,right);
}
++knt;
} // end of while
} //end of for
}
第二个元素的片段如下：
17 216
26 119
28 16
29 122
59 124
60 116
62 114
63 112
66 61
69 54
70 51
71 62
91 40
99 38
第3个元素的片段如下：
321 25
110 45
116 49
216 110
56 117
54 131
32 167
31 178
8 188
12 199
39 239
60 244
121 263
124 275
如果您有兴趣了解如何将原始文件的内容加载到'structure_a'中，则会给出下一篇文章。它工作正常。
for（q = 0; q＆lt; number_of_line_comparison_files; q ++）//遍历文件总数
75 223
61 248
45 278
31 290
10 291
111 311
117 324
128 338
139 347
148 365
167 376
178 381
191 394
193 397
} //结束了
答案 0 :(得分：0)
我必须说，应该有更多的信息，因为问题要完全清楚。 根据给定的数据，这是我的答案。至少我要问的部分是问的。 我希望它有所帮助。
// copy_pointer_struct.c
#include<stdio.h>
#include<stdlib.h>
int main(int argc, char* args[])
{
struct a
{
int left_line;
int right_line;
};
struct b
{
int conserved_left;
int conserved_right;
};
FILE *fp100;
fp100 = fopen("struct_file.txt", "a");
struct a* ptr1;
int structACapacity = 3;
ptr1=(struct a*)malloc(structACapacity*sizeof(struct a));
struct b *ptr2;
int structBCapacity = 1000;
ptr2=(struct b*)malloc(structBCapacity*sizeof(struct b));
// for writing test values to ptr1 array
int i;
for ( i = 0; i < structACapacity; i++ )
{
ptr1[i].left_line = i;
(ptr1+i)->right_line = i+1;
}
int structure_ctr,
number_of_line_comparison_files = 10,
knt;
// This outer for is neccessary only if you are getting structs form another source - a file for example or another structure.
//for(structure_ctr=0; structure_ctr < number_of_line_comparison_files; structure_ctr++)
{
// this inner for would be neccessary if you had an 2 dimensional array of structs or a pointer to a pointer to struct.
//for(knt=0; knt<500; knt++)
{
knt = 0;
// in your while condition there is no changing value, (change being made inside cycle or condition itself),
// which results in an infinite (for condition true) cycle or 0 cycles (for condition false)
// this particular condition works until we have reached 500th element or the end of array,
// whichever has lower value.
// Of course in case of use of outer for ( && knt < 500) wouldn't be used, depending of the goal you have.
while( (ptr1+knt) < (ptr1+structACapacity-1) && knt < 500 )
{
if( (ptr1+knt)->right_line == (ptr1+1+knt)->left_line ) // comment line for file test
{
// copying duplicate values to the struct b
int left = (ptr2+knt)->conserved_left = (ptr1+1+knt)->left_line;
int right = (ptr2+knt)->conserved_right = (ptr1+knt)->right_line;
// here you can write those values to a file as 2 integers, for example
fprintf(fp100,"%d %d\n", left, right);
}
++knt;
} // while
}//
} //for structure_ctr
fclose(fp100);
}
也许这种添加有助于：
// copy_pointer_struct.c
#include<stdio.h>
#include<stdlib.h>
typedef struct a
{
int left_line;
int right_line;
} structA;
typedef struct b
{
int conserved_left;
int conserved_right;
} structB;
int fillColumnPtr(FILE* source, structA* ptr);
int main(int argc, char* args[])
{
FILE *fp100;
fp100 = fopen("struct_file.txt", "w");
structA* ptr1;
int structACapacity = 1000;
ptr1=(structA*)malloc(structACapacity*sizeof(struct a));
printf("kapacitet ptr1: %d\n", sizeof ptr1);
structB *ptr2;
int structBCapacity = 1000;
ptr2=(struct b*)malloc(structBCapacity*sizeof(struct b));
char *filename = "columns_file4.txt";
FILE *cfile1 = fopen(filename, "r");
printf("Loading values from file: %s . . . \n", filename);
int number_of_lines = fillColumnPtr(cfile1, ptr1);
fclose(cfile1);
printf("Done.\n\n");
printf("Values loaded to ptr1(total lines %d):\n", number_of_lines);
int i;
for ( i = 0; i < number_of_lines; i++ )
{
printf("left: %6d, right: %6d\n", ptr1[i].left_line, ptr1[i].right_line);
}
printf("\nProcessing...\n");
int structure_ctr,
number_of_line_comparison_files = 10,
knt;
knt = 0;
while( (ptr1+knt) < (ptr1+structACapacity-1) && knt < number_of_lines )
{
if( (ptr1+knt)->right_line == (ptr1+1+knt)->left_line ) // comment line for file test
{
// copying duplicate values to the struct b
int left = (ptr2+knt)->conserved_left = (ptr1+1+knt)->left_line;
int right = (ptr2+knt)->conserved_right = (ptr1+knt)->right_line;
// here you can write those values to a file as 2 integers, for example
fprintf(fp100,"%d %d\n", left, right);
printf("%d %d\n", left, right);
}
++knt;
} // while
fclose(fp100);
}
// function: transfers data from a source file to pointer to struct
int fillColumnPtr(FILE* source, structA* ptr)
{
char file_line[20],
*str_left_line = calloc(sizeof(char), 6),
str_right_line[6];
int left_line, right_line, j, line_counter = 0, i = 0;
while ( fgets(file_line, 19, source) != NULL )
{
printf(">> fileline: %s", file_line);
for(j=0;j<6;j++)
{
str_left_line[j]=file_line[j];
str_right_line[j]=file_line[6+j];
}
left_line = atoi(str_left_line);
right_line = atoi(str_right_line);
printf(" left right: %-3d %6d\n", left_line, right_line);
ptr[i].left_line = left_line;
ptr[i].right_line = right_line;
++i;
++line_counter;
}
return line_counter;
}
注意：我检查了一些你应该在文件中的源值 - 它们中没有满足if内的条件，导致空指针。
附加发布，我已经测试了更改的值，它的工作原理。
对于此方法，请检查行中的间距
“columns_file4.txt”的内容：
321 25
25 45
116 49
216 110
110 117
54 131
32 167
31 178
178 188
12 199
199 239
60 244
121 263
124 275
//文件结束
在这个文件中有相同的值，例如：
（第1行右侧）25 ==（第2行左侧）25,110,178,199。
如果这不是您要查找的内容，请更改if条件。
祝好运。
希望这有帮助。