Invers

// ConsoleApplication1.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include "pch.h"
#include <iostream>

using namespace std;

int invers(int);
int main()
{
    int n;
    cin >> n;
    cout << invers(n);
}

int invers(int)
{
    /*
    Notatii:
     edi = nr
     esi = 10
     ebx = inv

     ALGORITM:
     inv=0
     while nr!=0 do
        nr/10=c rest r => inv=inv*10+r nr=c

     Cum facem impartirea:
     1.Facem edi/esi = eax rest edx ("edi/esi" adica "mov eax,edi" + "div esi")
     2.in ecx vom tine minte restul edx (edx e folosit by default la inmultire deci se sterge valoarea)
     rezultat=> inv=inv*10+ecx (inv=inv*10+nr%10) si edi(nr-ul)=eax ( nr=[nr/10])
     */
    _asm {
        mov edi,[ebp+8]
        mov esi,10
        mov ebx,0

        forInceput:
        cmp edi,0
        je stopFor

        mov eax,edi // mutam edi(nr-ul) in eax
        mov edx,0   // necesar ptr div
        div esi     // (edx::eax)/esi = eax rest edx  ( esi=10!!!)
        mov edi,eax // edi=[edi/10]

        //restul este adaugat la inv
        mov ecx,edx // tinem minte restul in ecx
        mov eax,ebx // mutam inversul in eax
        mul esi     // eax*esi= edx::eax => edx=0 si eax=inv*10
        mov ebx,eax // inv = inv*10
        add ebx,ecx // inv = inv*10 + n%10

        jmp forInceput
        stopFor:
        mov eax,ebx //eax returneaza deci salvam in el nr-ul
    }
}