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

```asm
<renduarene>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x318,%rsp
  mov    %rdi,0x8(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x308(%rsp)
  xor    %eax,%eax
  lea    0x10(%rsp),%r10
  sub    $0x26,%rdi
  lea    0x308(%rsp),%r14
  mov    %r10,%r8
  jmp    L635
L485:
  add    $0x1,%rax
  cmp    $0x26,%rax
  je     L841
L700:
  cmpb   $0x23,(%rdx,%rax,1)
  jne    L485
  cmpb   $0x23,0x1(%rcx,%rax,1)
  jne    L485
  cmpb   $0x23,0x1(%rsi,%rax,1)
  jne    L485
  cmpb   $0x23,-0x1(%rsi,%rax,1)
  jne    L485
  cmpb   $0x23,-0x1(%rcx,%rax,1)
  jne    L485
  movb   $0x20,(%rdx,%rax,1)
  movb   $0x20,(%r8,%rax,1)
  jmp    L485
L841:
  add    $0x26,%r8
  cmp    %r14,%r8
  je     L306
L635:
  mov    %rdi,%rcx
  add    $0x26,%rdi
  mov    %rdi,%rdx
  lea    0x4c(%rcx),%rsi
  mov    $0x0,%eax
  jmp    L700
L442:
  cmp    $0x23,%al
  je     L280
  cmp    $0x2e,%al
  jne    L311
  movb   $0x2e,(%rdi)
L311:
  mov    %edx,%r15d
  test   %edx,%edx
  sete   %al
  cmp    $0x25,%edx
  sete   %r8b
  test   %al,%al
  jne    L215
  test   %r8b,%r8b
  jne    L215
L263:
  test   %r15d,%r15d
  je     L146
  cmp    $0x25,%r15d
  je     L29
L241:
  add    $0x1,%rdx
  add    $0x1,%rsi
  add    $0x1,%rdi
  cmp    $0x26,%rdx
  je     L217
L789:
  mov    %rsi,%r8
  movzbl (%rsi),%eax
  cmp    $0x42,%al
  je     L433
  jle    L442
  cmp    $0x43,%al
  je     L270
  cmp    $0x4d,%al
  jne    L311
  movb   $0x4d,(%rdi)
  jmp    L311
L280:
  cmpb   $0x23,(%r12,%rdx,1)
  je     L502
  cmpb   $0x23,0x1(%rsi)
  je     L522
  cmpb   $0x23,(%r9,%rdx,1)
  je     L130
L123:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L53
  cmpb   $0x23,-0x1(%r8)
  je     L97
L53:
  cmpb   $0x23,(%r9,%rdx,1)
  jne    L311
  cmpb   $0x23,-0x1(%r8)
  je     L311
  movb   $0xba,(%rdi)
  jmp    L311
L522:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L521
L71:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L798
  cmpb   $0x23,-0x1(%r8)
  je     L191
L798:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L304
L487:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L311
  cmpb   $0x23,-0x1(%r8)
  je     L311
  movb   $0xcd,(%rdi)
  jmp    L311
L521:
  cmpb   $0x23,-0x1(%rsi)
  je     L71
  movb   $0xc9,(%rdi)
  jmp    L71
L130:
  cmpb   $0x23,-0x1(%r8)
  jne    L123
  movb   $0xbb,(%rdi)
  jmp    L123
L719:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L437
  cmpb   $0x23,-0x1(%r8)
  je     L437
  movb   $0xc8,(%rdi)
L437:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L288
  cmpb   $0x23,-0x1(%r8)
  je     L790
L288:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L742
L393:
  cmpb   $0x23,(%r9,%rdx,1)
  jne    L311
  cmpb   $0x23,-0x1(%r8)
  jne    L311
  movb   $0xce,(%rdi)
  jmp    L311
L13:
  movb   $0xbc,(%rdi)
  jmp    L649
L191:
  movb   $0xcd,(%rdi)
  jmp    L798
L296:
  cmpb   $0x23,-0x1(%r8)
  je     L353
  movb   $0xba,(%rdi)
  jmp    L353
L48:
  cmpb   $0x23,-0x1(%r8)
  jne    L717
  movb   $0xb9,(%rdi)
  jmp    L717
L790:
  movb   $0xca,(%rdi)
  jmp    L288
L304:
  cmpb   $0x23,-0x1(%r8)
  jne    L487
  movb   $0xcb,(%rdi)
  jmp    L487
L742:
  cmpb   $0x23,-0x1(%r8)
  je     L393
  movb   $0xcc,(%rdi)
  jmp    L393
L97:
  movb   $0xcd,(%rdi)
  jmp    L53
L270:
  movb   $0x43,(%rdi)
  jmp    L311
L433:
  movb   $0x4,(%rdi)
  jmp    L311
L215:
  test   %ecx,%ecx
  je     L504
  cmp    $0x13,%ecx
  je     L504
  movb   $0xba,(%rdi)
  jmp    L263
L504:
  cmp    $0x13,%ecx
  jne    L666
  test   %al,%al
  je     L666
  movb   $0xc8,0x2e2(%rsp)
L146:
  cmp    $0xf,%ecx
  ja     L241
  test   %r13,%r13
  je     L241
  movb   $0xcc,(%rbx)
  jmp    L241
L666:
  test   %ecx,%ecx
  jne    L263
  test   %r8b,%r8b
  je     L263
  movb   $0xbb,0x35(%rsp)
L29:
  cmp    $0xf,%ecx
  ja     L241
  test   %r11,%r11
  je     L241
  movb   $0xb9,0x25(%rbx)
  add    $0x1,%ecx
  add    $0x26,%rbx
  add    $0x26,%rbp
L259:
  lea    -0x4c(%rbp),%r12
  mov    %rbp,%r9
  lea    -0x26(%rbp),%rsi
  mov    %rbx,%rdi
  mov    $0x0,%edx
  mov    $0xaac0,%r11d
  shr    %cl,%r11
  and    $0x1,%r11d
  mov    $0x8ac0,%r13d
  shr    %cl,%r13
  and    $0x1,%r13d
  jmp    L789
L217:
  add    $0x1,%ecx
  add    $0x26,%rbx
  add    $0x26,%rbp
  cmp    $0x14,%ecx
  jne    L259
  mov    0x8(%rsp),%rsi
L669:
  mov    %rsi,%rcx
  mov    $0x0,%eax
L724:
  movzbl (%r10,%rax,1),%edx
  mov    %dl,(%rcx,%rax,1)
  add    $0x1,%rax
  cmp    $0x26,%rax
  jne    L724
  add    $0x26,%r10
  add    $0x26,%rsi
  cmp    %r14,%r10
  jne    L669
  mov    0x308(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L395
  add    $0x318,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L306:
  mov    0x8(%rsp),%rax
  lea    0x26(%rax),%rbp
  mov    %r10,%rbx
  mov    $0x0,%ecx
  jmp    L259
L502:
  cmpb   $0x23,0x1(%rsi)
  je     L719
  cmpb   $0x23,(%r9,%rdx,1)
  je     L649
  cmpb   $0x23,-0x1(%r8)
  je     L13
L649:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L296
L353:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L48
L717:
  cmpb   $0x23,(%r9,%rdx,1)
  je     L311
  cmpb   $0x23,-0x1(%r8)
  je     L311
  movb   $0xba,(%rdi)
  jmp    L311
L395:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void renduarene(char terrain[20][38]) {
  int i, j;
  char betterterrain[20][38];
  for (i = 0; i < 20; i++) {
    for (j = 0; j < 38; j++) {
      if (terrain[i][j] == '#' && terrain[i - 1][j + 1] == '#' && terrain[i + 1][j + 1] == '#' && terrain[i + 1][j - 1] == '#' && terrain[i - 1][j - 1] == '#') {
        terrain[i][j] = ' ';
        betterterrain[i][j] = ' ';
      }
    }
  }
  for (i = 0; i < 20; i++) {
    for (j = 0; j < 38; j++) {
      switch (terrain[i][j]) {
      case '#':
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xC9;
        }
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xBB;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xC8;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xBC;
        }
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xCD;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xBA;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xB9;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xCA;
        }
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xCB;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xCC;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xCE;
        }
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] == '#') {
          betterterrain[i][j] = (char)0xCD;
        }
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] == '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xCD;
        }
        if (terrain[i - 1][j] != '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] == '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xBA;
        }
        if (terrain[i - 1][j] == '#' && terrain[i][j + 1] != '#' && terrain[i + 1][j] != '#' && terrain[i][j - 1] != '#') {
          betterterrain[i][j] = (char)0xBA;
        }
        break;
      case '.':
        betterterrain[i][j] = '.';
        break;
      case 'C':
        betterterrain[i][j] = 'C';
        break;
      case 'M':
        betterterrain[i][j] = 'M';
        break;
      case 'B':
        betterterrain[i][j] = (char)0x4;
        break;
      }
      if ((j == 0 || j == 37) && (i != 0 && i != 19)) {
        betterterrain[i][j] = (char)0xBA;
      }
      if (j == 0 && i == 19) {
        betterterrain[i][j] = (char)0xC8;
      }
      if (j == 37 && i == 0) {
        betterterrain[i][j] = (char)0xBB;
      }
      if (j == 0 && (i == 6 || i == 7 || i == 9 || i == 11 || i == 15)) {
        betterterrain[i][j] = (char)0xCC;
      }
      if (j == 37 && (i == 6 || i == 7 || i == 9 || i == 11 || i == 13 || i == 15)) {
        betterterrain[i][j] = (char)0xB9;
      }
    }
  }
  for (i = 0; i < 20; i++) {
    for (j = 0; j < 38; j++) {
      terrain[i][j] = betterterrain[i][j];
    }
  }
}
```