user: Please show me the C implementation that matches the assembly code listed below:

```asm
<levenshtein>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x28,%rsp
  mov    %rdi,%rbp
  mov    %rsi,%r12
  call   <strlen@plt>
  mov    %rax,%r14
  mov    %rax,%r15
  mov    %r12,%rdi
  call   <strlen@plt>
  mov    %rax,%rbx
  mov    %rax,%r13
  lea    0x1(%rax),%rdi
  mov    $0x4,%esi
  call   <calloc@plt>
  mov    %rax,%r9
  test   %r14,%r14
  je     L171
  test   %rbx,%rbx
  je     L171
L105:
  movzbl (%r12),%eax
  cmp    %al,0x0(%rbp)
  jne    L171
  add    $0x1,%rbp
  add    $0x1,%r12
  sub    $0x1,%r13
  sub    $0x1,%r15
  je     L171
  test   %r13,%r13
  jne    L105
L171:
  mov    %r13d,%eax
  test   %r15,%r15
  je     L74
  mov    %r15d,%eax
  test   %r13,%r13
  je     L74
  mov    $0x0,%eax
  mov    $0x0,%edx
  mov    %r13,%rcx
  add    $0x1,%rcx
  je     L157
L137:
  mov    %eax,(%r9,%rdx,4)
  add    $0x1,%eax
  mov    %eax,%edx
  cmp    %rcx,%rdx
  jb     L137
L157:
  lea    (%r9,%r13,4),%rax
  mov    %rax,0x10(%rsp)
  movl   $0xffffffff,0xc(%rsp)
  mov    $0x0,%ebx
  mov    $0x0,%r10d
  mov    $0x0,%r11d
  mov    %r15,0x18(%rsp)
  jmp    L116
L70:
  mov    $0x1,%edx
L94:
  lea    (%r9,%rcx,4),%r14
  add    $0x1,%edi
  mov    %edi,%ecx
  mov    (%r9,%rcx,4),%eax
  lea    0x1(%rax),%esi
  lea    0x1(%r8),%eax
  cmp    %eax,%esi
  cmovbe %esi,%eax
  add    (%r14),%edx
  cmp    %edx,%eax
  cmova  %edx,%eax
  mov    %r8d,(%r14)
  cmp    %r13,%rcx
  jae    L99
  mov    %eax,%r8d
L133:
  movzbl 0x0(%rbp,%r10,1),%esi
  movzbl (%r12,%rcx,1),%eax
  mov    %r11d,%edx
  cmp    %al,%sil
  je     L94
  test   %r15d,%r15d
  je     L70
  test   %edi,%edi
  je     L70
  mov    $0x1,%edx
  mov    (%rsp),%r14
  cmp    0x0(%rbp,%r14,1),%al
  jne    L94
  lea    -0x1(%rdi),%eax
  cmp    %sil,(%r12,%rax,1)
  setne  %dl
  movzbl %dl,%edx
  jmp    L94
L99:
  mov    0x10(%rsp),%rdi
  mov    %eax,(%rdi)
  mov    %ebx,%r10d
  addl   $0x1,0xc(%rsp)
  cmp    0x18(%rsp),%r10
  jae    L173
L116:
  mov    %ebx,%r15d
  add    $0x1,%ebx
  mov    %ebx,%r8d
  mov    $0x0,%edi
  mov    $0x0,%ecx
  mov    0xc(%rsp),%eax
  mov    %rax,(%rsp)
  jmp    L133
L173:
  mov    %eax,%ebx
  mov    %r9,%rdi
  call   <free@plt>
  mov    %ebx,%eax
L74:
  add    $0x28,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
int levenshtein(const char *str1, const char *str2) {
  size_t len1 = strlen(str1), len2 = strlen(str2);
  unsigned int *v = calloc(len2 + 1, sizeof(unsigned int));
  unsigned int i, j, current, next, cost;
  while (len1 > 0 && len2 > 0 && ((str1[0]) == (str2[0])))
    str1++, str2++, len1--, len2--;
  if (!len1)
    return (len2);
  if (!len2)
    return (len1);
  for (j = 0; j < len2 + 1; j++)
    v[j] = j;
  for (i = 0; i < len1; i++) {
    current = i + 1;
    for (j = 0; j < len2; j++) {
      cost = !(((str1[i]) == (str2[j])) || (i && j && ((str1[i - 1]) == (str2[j])) && ((str1[i]) == (str2[j - 1]))));
      next = ((((v[j + 1] + 1) < (current + 1) ? (v[j + 1] + 1) : (current + 1))) < (v[j] + cost) ? (((v[j + 1] + 1) < (current + 1) ? (v[j + 1] + 1) : (current + 1))) : (v[j] + cost));
      v[j] = current;
      current = next;
    }
    v[len2] = next;
  }
  free(v);
  return (next);
}
```