V>тоже допустил ошибку в одном из вариантов

S>long avg(long a, long b, long c)
S>{
S>  return (a+b+c)/3; 
S>}
S>

long avg(long a,long b,long c) {
    long r1=(a>>2)+(b>>2)+(c>>2), r2=r1%3; 
    r1-=r2; r2=4*r2+(a&3)+(b&3)+(c&3);
    if (r1<0 && r2>0) { r2-=12; r1++; }
    r1/=3; r2/=3; return (r1<<2)+r2;
}

S>>long avg(long a, long b, long c)
S>>{
S>>  return (a+b+c)/3; 
S>>}
S>>

_>Переполнение можно убрать, заменив одни UB на другие

_>long avg(long a,long b,long c) {
_>    long r1=(a>>2)+(b>>2)+(c>>2), r2=r1%3; 
_>    r1-=r2; r2=4*r2+(a&3)+(b&3)+(c&3);
_>    if (r1<0 && r2>0) { r2-=12; r1++; }
_>    r1/=3; r2/=3; return (r1<<2)+r2;
_>}
_>

long avg(long a, long b, long c)
{
  long ar = a % 3, br = b % 3, cr = b % 3;
  return a / 3 + b / 3 + c / 3 + (ar+br+cr) / 3
}

long avg3(long a,long b,long c) {
    auto ad = std::ldiv(a, 3);
    auto bd = std::ldiv(b, 3);
    auto cd = std::ldiv(c, 3);
    return ad.quot + bd.quot + cd.quot + (ad.rem + bd.rem + cd.rem)/3;
}

    mov rax, 7FFFFFFF7FFFFFFFh
    inc eax

    mov rax, 7FFFFFFF7FFFFFFFh
    inc al

PUBLIC is_max

.code

is_max PROC
    ; скопируй сюда интересующий тебя код и ходи пошагово
    ret
is_max ENDP

END

#include <iostream>

extern "C" bool is_max(int);

int main()
{
    using namespace std;

    bool r = is_max(0x7FFFFFFF);
    cout << r << endl;

    return 0;
}

struct Index {
    unsigned long long i_;
    explicit constexpr Index(const auto i) : i_(i) {}
};

Index operator ""_i(unsigned long long i) {
    return Index(i);
}

auto i = 1_i;

using System;
using System.Runtime.CompilerServices;

interface IYesNo { 
    bool Value { get; }
}

struct Yes : IYesNo {
    public bool Value => true;
}

struct No : IYesNo {
    public bool Value => false;
}

class SomeType<TConfig> where TConfig : struct, IYesNo
{
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void Method() {
        if(default(TConfig).Value) {
            Console.WriteLine("Yes");
        }
        else {
            Console.WriteLine("No");
        }
    }
}

class Program
{
    static void Main()  { 
        SomeType<Yes>.Method();
        SomeType<No>.Method();
    }
}

Program:Main() (FullOpts):
       push     rbp
       mov      rbp, rsp
       mov      rdi, 0x7F2C74BD06E8      ; 'Yes'
       call     [System.Console:WriteLine(System.String)]
       mov      rdi, 0x7F2C74BD0708      ; 'No'
       call     [System.Console:WriteLine(System.String)]
       nop      
       pop      rbp
       ret

Program:Main():
       push     rbp
       sub      rsp, 16
       lea      rbp, [rsp+10H]
       mov      byte  ptr [rbp-08H], 0
       lea      rdi, bword ptr [rbp-08H]
       mov      byte  ptr [rdi], 0
       mov      rdi, qword ptr [(reloc)]
       mov      rdi, gword ptr [rdi]
       call     [System.Console:WriteLine(System.String)]
       mov      byte  ptr [rbp-10H], 0
       lea      rdi, bword ptr [rbp-10H]
       mov      byte  ptr [rdi], 0
       mov      rdi, qword ptr [(reloc)]
       mov      rdi, gword ptr [rdi]
       call     [System.Console:WriteLine(System.String)]
       nop      
       add      rsp, 16
       pop      rbp
       ret

Program:IsMax(int):bool:
       lea      eax, [rdi+01H]
       cmp      eax, edi
       setl     al
       movzx    rax, al
       ret

using System;

class SomeClass {
    public void Method() {
        Console.WriteLine("!!!");
    }
}

class Program
{
    static void Main()
    {
        SomeClass? sc = null;
        var s = Console.ReadLine();
        if(s.Length > 1)
          sc = new SomeClass();

        sc.Method();
    }
}

cmp      byte  ptr [rbx], bl

#include <iostream>

using namespace std;

struct SomeObj {
    void Method() {
        std::cout << "!!!" << std::endl;
    }
};

int main()
{
    int i;
    cin >> i;

    SomeObj * obj = nullptr;

    if(i > 0)
        obj = new SomeObj();

    obj->Method();

    return 0;
}