user: What is the c source code of the assembly code below:

```asm
<lcsq>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %rdi,%r12
  push   %rbx
  mov    %rsi,%rbx
  sub    $0x38,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    %rbx,%rdi
  mov    %rax,-0x48(%rbp)
  lea    0x1(%rax),%r13d
  call   <strlen@plt>
  mov    %rax,-0x58(%rbp)
  lea    0x1(%rax),%r15d
  mov    %rsp,%rax
  cmp    %rax,%rsp
  je     L118
L181:
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  cmp    %rax,%rsp
  jne    L181
L118:
  sub    $0x400,%rsp
  orq    $0x0,0x3f8(%rsp)
  mov    $0x4,%esi
  mov    %r13d,%edi
  mov    %rsp,-0x60(%rbp)
  imul   %r15d,%edi
  movslq %edi,%rdi
  call   <calloc@plt>
  movslq %r13d,%rdi
  shl    $0x3,%rdi
  mov    %rax,-0x50(%rbp)
  call   <malloc@plt>
  mov    %rax,%r14
  test   %r13d,%r13d
  jle    L146
  mov    -0x48(%rbp),%esi
  movslq %r15d,%rcx
  mov    -0x50(%rbp),%rdx
  shl    $0x2,%rcx
  lea    0x8(%rax,%rsi,8),%rsi
  nopw   0x0(%rax,%rax,1)
L111:
  mov    %rdx,(%rax)
  add    $0x8,%rax
  add    %rcx,%rdx
  cmp    %rax,%rsi
  jne    L111
L146:
  movzbl (%r12),%r9d
  test   %r9b,%r9b
  je     L29
  movzbl (%rbx),%r15d
  mov    %r14,%r11
  mov    %r12,%r13
  nopl   0x0(%rax,%rax,1)
L74:
  test   %r15b,%r15b
  je     L180
  mov    (%r11),%r8
  mov    0x8(%r11),%rdi
  mov    %rbx,%rcx
  mov    %r15d,%edx
  mov    $0x4,%eax
  jmp    L131
  nopl   0x0(%rax)
L197:
  mov    (%r8,%rax,1),%edx
  mov    -0x4(%rdi,%rax,1),%r10d
  cmp    %r10d,%edx
  cmovl  %r10d,%edx
L64:
  add    $0x1,%rcx
  mov    %edx,(%rsi)
  add    $0x4,%rax
  movzbl (%rcx),%edx
  test   %dl,%dl
  je     L180
L131:
  lea    (%rdi,%rax,1),%rsi
  cmp    %r9b,%dl
  jne    L197
  mov    -0x4(%r8,%rax,1),%edx
  add    $0x1,%edx
  jmp    L64
  nopl   0x0(%rax)
L180:
  movzbl 0x1(%r13),%r9d
  add    $0x1,%r13
  add    $0x8,%r11
  test   %r9b,%r9b
  jne    L74
L29:
  mov    -0x60(%rbp),%rax
  mov    -0x48(%rbp),%rbx
  movb   $0x0,0x3ff(%rax)
  lea    0x3ff(%rax),%r13
  mov    %ebx,%edx
  mov    -0x58(%rbp),%rax
  mov    %eax,%esi
  test   %eax,%eax
  jle    L24
  test   %ebx,%ebx
  jg     L193
  jmp    L24
  nopw   0x0(%rax,%rax,1)
L127:
  sub    $0x1,%esi
  cmp    -0x4(%rdi,%r10,1),%r8d
  je     L153
  movzbl -0x1(%r12,%rcx,1),%eax
  sub    $0x1,%edx
  sub    $0x1,%r13
  mov    %al,0x0(%r13)
L153:
  test   %edx,%edx
  jle    L24
L166:
  test   %esi,%esi
  jle    L24
L193:
  movslq %edx,%rcx
  movslq %esi,%rax
  mov    (%r14,%rcx,8),%rdi
  mov    -0x8(%r14,%rcx,8),%r9
  lea    0x0(,%rax,4),%r10
  mov    (%rdi,%rax,4),%r8d
  cmp    (%r9,%rax,4),%r8d
  jne    L127
  sub    $0x1,%edx
  test   %edx,%edx
  jg     L166
  nopl   0x0(%rax,%rax,1)
L24:
  mov    -0x50(%rbp),%rdi
  call   <free@plt>
  mov    %r14,%rdi
  call   <free@plt>
  mov    %r13,%rdi
  call   <strdup@plt>
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  jne    L28
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
L28:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
char *lcsq(const char *a, const char *b) {
  int lena = strlen(a) + 1;
  int lenb = strlen(b) + 1;
  int bufrlen = 1024;
  char bufr[bufrlen], *result;
  int i, j;
  const char *x, *y;
  int *la = calloc(lena * lenb, sizeof(int));
  int **lengths = malloc(lena * sizeof(int *));
  for (i = 0; i < lena; i++)
    lengths[i] = la + i * lenb;
  for (i = 0, x = a; *x; i++, x++) {
    for (j = 0, y = b; *y; j++, y++) {
      if (*x == *y) {
        lengths[i + 1][j + 1] = lengths[i][j] + 1;
      } else {
        int ml = (((lengths[i + 1][j]) > (lengths[i][j + 1])) ? (lengths[i + 1][j]) : (lengths[i][j + 1]));
        lengths[i + 1][j + 1] = ml;
      }
    }
  }
  result = bufr + bufrlen;
  *--result = '\0';
  i = lena - 1;
  j = lenb - 1;
  while ((i > 0) && (j > 0)) {
    if (lengths[i][j] == lengths[i - 1][j])
      i -= 1;
    else if (lengths[i][j] == lengths[i][j - 1])
      j -= 1;
    else {
      *--result = a[i - 1];
      i -= 1;
      j -= 1;
    }
  }
  free(la);
  free(lengths);
  return strdup(result);
}
```