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

```asm
<qsort>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %esi,0x24(%rsp)
  mov    %edx,0x38(%rsp)
  cmp    %esi,%edx
  jle    L93
  mov    %rdi,%r14
L9:
  mov    0x24(%rsp),%ebx
  mov    0x38(%rsp),%edx
  mov    %r14,%rdi
  mov    %r14,%r15
  mov    %ebx,%esi
  mov    %ebx,0x20(%rsp)
  call   <partition@plt>
  mov    %eax,0x24(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x2c(%rsp)
  cmp    %ebx,%eax
  jle    L161
L41:
  mov    0x20(%rsp),%ebx
  mov    0x2c(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x14(%rsp)
  call   <partition@plt>
  mov    %eax,0x20(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x30(%rsp)
  cmp    %ebx,%eax
  jle    L149
L16:
  mov    0x14(%rsp),%ebx
  mov    0x30(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x18(%rsp)
  call   <partition@plt>
  mov    %eax,0x14(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x34(%rsp)
  cmp    %ebx,%eax
  jle    L40
L140:
  mov    0x18(%rsp),%ebx
  mov    0x34(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  call   <partition@plt>
  mov    %eax,0x18(%rsp)
  lea    -0x1(%rax),%r13d
L121:
  cmp    %ebx,%r13d
  jle    L159
L79:
  mov    %ebx,%esi
  mov    %r13d,%edx
  mov    %r15,%rdi
  mov    %ebx,%r14d
  call   <partition@plt>
  lea    -0x1(%rax),%r12d
  mov    %eax,%ebx
  cmp    %r14d,%r12d
  jle    L121
  mov    %eax,0xc(%rsp)
  mov    %r12d,%ebx
  mov    %r13d,0x8(%rsp)
  mov    %r15,%r13
L23:
  mov    %r14d,%esi
  mov    %ebx,%edx
  mov    %r13,%rdi
  mov    %r14d,%ebp
  call   <partition@plt>
  mov    %eax,%r14d
  lea    -0x1(%rax),%eax
  mov    %eax,0x1c(%rsp)
  cmp    %ebp,%eax
  jle    L78
  mov    %ebx,0x10(%rsp)
  mov    %r13,%rbx
L20:
  mov    0x1c(%rsp),%edx
  mov    %ebp,%esi
  mov    %rbx,%rdi
  mov    %ebp,%r12d
  call   <partition@plt>
  lea    -0x1(%rax),%r13d
  mov    %eax,%ebp
  cmp    %r12d,%r13d
  jle    L107
  mov    %eax,0x28(%rsp)
  mov    %rbx,%rbp
  mov    %r13d,%ebx
L66:
  mov    %r12d,%esi
  mov    %ebx,%edx
  mov    %rbp,%rdi
  mov    %r12d,%r15d
  call   <partition@plt>
  lea    -0x1(%rax),%r13d
  mov    %eax,%r12d
  cmp    %r15d,%r13d
  jle    L70
  mov    %r14d,%ecx
  mov    %ebx,%r12d
  mov    %eax,%r14d
  mov    %r13d,%ebx
L177:
  mov    %r15d,%esi
  mov    %ebx,%edx
  mov    %rbp,%rdi
  mov    %ecx,0x3c(%rsp)
  call   <partition@plt>
  mov    %r15d,%r13d
  mov    %rbp,%rdi
  mov    %eax,%r15d
  lea    -0x1(%rax),%edx
  mov    %r13d,%esi
  call   <qsort>
  cmp    %r15d,%ebx
  mov    0x3c(%rsp),%ecx
  jg     L177
  mov    %r12d,%ebx
  mov    %r14d,%r12d
  mov    %ecx,%r14d
L70:
  cmp    %r12d,%ebx
  jg     L66
  mov    %rbp,%rbx
  mov    0x28(%rsp),%ebp
L107:
  cmp    %ebp,0x1c(%rsp)
  jg     L20
  mov    %rbx,%r13
  mov    0x10(%rsp),%ebx
L78:
  cmp    %r14d,%ebx
  jg     L23
  mov    %r13,%r15
  mov    0xc(%rsp),%ebx
  mov    0x8(%rsp),%r13d
  cmp    %ebx,%r13d
  jg     L79
L159:
  mov    0x18(%rsp),%ecx
  cmp    %ecx,0x34(%rsp)
  jg     L140
L40:
  mov    0x14(%rsp),%ecx
  cmp    %ecx,0x30(%rsp)
  jg     L16
L149:
  mov    0x20(%rsp),%ecx
  cmp    %ecx,0x2c(%rsp)
  jg     L41
  mov    %r15,%r14
L161:
  mov    0x24(%rsp),%ecx
  cmp    %ecx,0x38(%rsp)
  jg     L9
L93:
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void qsort(int a[], int begin, int end) {
  int m;
  if (begin < end) {
    m = partition(a, begin, end);
    qsort(a, begin, m - 1);
    qsort(a, m, end);
  }
}
```