CODEWITHSUNDEEP
c++algorithmassemblyx86-16
Alex
Alex

Reputation: 3190

Assembler task - min and max values of the array

I've encountered problems with assembler code. I'm a newbie to assembler, so it seems difficult for me to solve it myself.

The task is: "To find minimal and maximal elements of the array."

All I've already done is searching for maximal element. I can't find out, how to make check for the minimal element and where I should put such verification. Or, probably, I should loop through elements second time after finding maximal element?

Code:

#include <conio.h>
#include <stdio.h>
#include <iostream.h>
void main() {
   int  N = 10, i;
   clrscr();
   // on this platform, int is 16-bit
   int a[] = { 1, 4, -6, 12, -25, 10, 3, -4, 15, 7}, MAX, MIN, RESULT;

    __asm{
    mov cx, N
    lea si, a
    lodsw
    mov bx, ax
    mov dx, ax
    dec cx }
    m:
       __asm{
     lodsw
     cmp dx, ax
     jge m1
     mov dx, ax
       }
    m1:
       __asm{
       loop m
       mov MAX, dx
    }

cout << "Max = " << MAX;
//cout << "Min = " << MIN;
getch();
}

Upvotes: 0

Views: 3431

Answers (2)

Alex
Alex

Reputation: 3190

If it's interesting to someone, here is the solution for my question(I found out it today with help of my tutor):

#include <conio.h>
#include <stdio.h>
#include <iostream.h>
void main() {
   int  N = 10, i;
   clrscr();
   int a[] = { 1, 4, -6, 12, -25, 10, 3, -4, 15, 7}, MAX, MIN, RESULT;

    __asm{
      mov cx, N
      lea si, a
      lodsw
      mov MIN, ax
      mov MAX, ax
      dec cx
    }
    m:
     __asm{
       lodsw
       cmp MIN, ax
       jle m1
       mov MIN, ax
       jmp m2
    }
    m1:
     __asm{
       cmp MAX, ax
       jge m2
       mov MAX, ax
    }
    m2:
     __asm{
       loop m;
    }

cout << "Max = " << MAX << "\n";
cout << "Min = " << MIN;
getch();
}

Algorithm: if cmp MIN, ax has negative result, it means ax is greater, than MIN. So script jumps to m1 label to compare ax value with MAX. When cmp MIN, ax returns positive value, scripts assigns value of ax register to MIN variable and after that jumps to the m2 label to decrement loop counter. Algorithm of finding maximal value works similarly(label m1).

Upvotes: 0

Wayne Conrad
Wayne Conrad

Reputation: 108049

What happens if you replace "jge" with "jle"? Try it and see.

Upvotes: 3

Related Questions