Simple join computing

Implement the sum of N1 +... + N2 for example: 43 + 44 +... + 63

 

Algorithm: N1 +... + n2 = (N1 + N2) * (n2-n1 + 1)/2

 

 

 

. 386
. Model stdcall, flat
Option Casemap: None

Includelib msvcrt. Lib
Printf proto C: DWORD,: vararg
Scanf proto C: DWORD,: vararg

. Data?
Num1 dd?
Num2 dd? ; // Result = num1 +... + num2
. Data
Szmsg dB 'Please input two num (for example: 43,63): ', 0
Szres dB '% d, % d', 0
Szfmt dB '% d +... + % d = % d', 0dh, 0ah, 0
. Code
Start:

Invoke printf, offset szmsg
Invoke scanf, offset szres, offset num1, offset num2

 

MoV eax, num1
Add eax, num2

MoV edX, num2
INC edX
Sub edX, num1
 
Mul edX
SAR eax, 1

Invoke printf, offset szfmt, num1, num2, eax
 
RET
End start

 

 

; /// Ml/C/coff my. ASM
; // Link/subsystem: Console My. OBJ