user: 请将这段汇编代码片段转换成等效的C代码:

```asm
<main>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  lea    D50(%rip),%rsi
  lea    D42(%rip),%rdi
  call   <fopen@plt>
  mov    %rax,%rbp
  mov    %rax,(%rsp)
  lea    D7(%rip),%rsi
  lea    D59(%rip),%rdi
  call   <fopen@plt>
  mov    %rax,0x8(%rsp)
  mov    $0x1a,%edi
  call   <malloc@plt>
  mov    %rax,%rbx
  mov    $0x1a,%edi
  call   <malloc@plt>
  mov    %rax,%r15
  mov    $0x1a,%edi
  call   <malloc@plt>
  mov    %rax,%r14
  mov    %rbp,%rdi
  call   <fgetc@plt>
  mov    %eax,%r13d
  mov    $0x1a,%esi
  mov    %rbx,%rdi
  call   <zeroStr@plt>
  mov    $0x1a,%esi
  mov    %r15,%rdi
  call   <zeroStr@plt>
  mov    $0x1a,%esi
  mov    %r14,%rdi
  call   <zeroStr@plt>
  mov    %rbx,%rdi
  call   <puts@plt>
  mov    %r15,%rdi
  call   <puts@plt>
  mov    %r14,%rdi
  call   <puts@plt>
  mov    $0x33,%r12d
  jmp    L79
L56:
  cmpb   $0x30,(%rbx)
  je     L52
  mov    $0x1,%eax
L53:
  lea    (%rbx,%rax,1),%rdx
  mov    %rax,%rbp
  add    $0x1,%rax
  cmpb   $0x30,-0x1(%rbx,%rax,1)
  jne    L53
L18:
  mov    %r13b,(%rdx)
  mov    (%rsp),%rdi
  call   <fgetc@plt>
  mov    %eax,%r13d
  mov    %al,(%r15,%rbp,1)
L65:
  sub    $0x1,%r12d
  je     L0
L79:
  movsbl %r13b,%ebp
  mov    $0x1a,%edx
  mov    %rbx,%rsi
  mov    %ebp,%edi
  call   <charExists@plt>
  test   %rax,%rax
  je     L56
  mov    %rbx,%rsi
  mov    %ebp,%edi
  call   <charLoc@plt>
  mov    %eax,%ebp
  mov    (%rsp),%rdi
  call   <fgetc@plt>
  mov    %eax,%r13d
  movslq %ebp,%rbp
  mov    %al,(%r14,%rbp,1)
  jmp    L65
L52:
  mov    %rbx,%rdx
  mov    $0x0,%ebp
  jmp    L18
L0:
  mov    %rbx,%rdi
  call   <puts@plt>
  mov    %r15,%rdi
  call   <puts@plt>
  mov    %r14,%rdi
  call   <puts@plt>
  mov    $0x0,%eax
  mov    $0x0,%ebx
L11:
  movzbl (%r14,%rax,1),%ecx
  cmp    %cl,(%r15,%rax,1)
  sete   %dl
  movzbl %dl,%edx
  add    %edx,%ebx
  add    $0x1,%rax
  cmp    $0x1a,%rax
  jne    L11
  mov    %ebx,%esi
  lea    D25(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    %ebx,%edx
  lea    D9(%rip),%rsi
  mov    0x8(%rsp),%rdi
  call   <fprintf@plt>
  mov    $0x0,%eax
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

tool_calls: name: unpack_data
arguments: tag: D50
type_infered: string
name: unpack_data
arguments: tag: D42
type_infered: string
name: unpack_data
arguments: tag: D7
type_infered: string
name: unpack_data
arguments: tag: D59
type_infered: string
name: unpack_data
arguments: tag: D25
type_infered: string
name: unpack_data
arguments: tag: D9
type_infered: string

tool: D50: r

tool: D42: circlecross.in

tool: D7: w

tool: D59: circlecross.out

tool: D25: Crossing Pairs: %d


tool: D9: %d


assistant: ```c
int main(void) {
  FILE *fl = fopen("circlecross.in", "r");
  FILE *fout = fopen("circlecross.out", "w");
  char *cows = malloc(sizeof(char) * 26);
  char *entryPair = malloc(sizeof(char) * 26);
  char *exitPair = malloc(sizeof(char) * 26);
  int i;
  char cow = fgetc(fl);
  int pos;
  int cowLoc;
  int pair;
  int pairs = 0;
  zeroStr(cows, 26);
  zeroStr(entryPair, 26);
  zeroStr(exitPair, 26);
  printf("%s\n", cows);
  printf("%s\n", entryPair);
  printf("%s\n", exitPair);
  for (i = 0; i < 51; i++) {
    if (charExists(cow, cows, 26) == 0) {
      pos = 0;
      while (*(cows + pos) != '0') {
        pos++;
      }
      *(cows + pos) = cow;
      pair = fgetc(fl);
      *(entryPair + pos) = pair;
      cow = pair;
    } else {
      cowLoc = charLoc(cow, cows);
      pair = fgetc(fl);
      *(exitPair + cowLoc) = pair;
      cow = pair;
    }
  }
  printf("%s\n", cows);
  printf("%s\n", entryPair);
  printf("%s\n", exitPair);
  pos = 0;
  while (pos < 26) {
    if (*(entryPair + pos) == *(exitPair + pos)) {
      pairs++;
    }
    pos++;
  }
  printf("Crossing Pairs: %d\n", pairs);
  fprintf(fout, "%d\n", pairs);
}
```