Question

用汇编语言写2~20的偶数相加的程序如何写

用汇编语言写2~20的偶数相加的程序如何写

Answer 1

code segment
assume cs:code,ds:code
start:mov ax,code
mov ds,ax
mov ax,0 ;累加器清0
mov cx,20
L1: test cx,1 ;cx为奇数跳过
jnz skip
add ax,cx ;加偶数
skip: loop L1
mov sum,ax ;累加和送内存
MOV AH,0
INT 16H
MOV AX,4C00H
INT 21H
sum dw ?
code ends
end start

Answer 2

code
segment
assume
cs:code,ds:code
start:mov
ax,code
mov
ds,ax
mov
ax,2
xor
cx,cx
;cx存结果值
L1:
add
cx,ax
add
ax,2
cmp
ax,20
jl
L1
MOV
AH,0
INT
16H
MOV
AX,4C00H
INT
21H
code
ends
end
start

Answer 3

code segment
assume cs:code,ds:code
start:mov ax,code
mov ds,ax
mov ax,2
xor cx,cx ;cx存结果值
L1:
add cx,ax
add ax,2
cmp ax,20
jl L1
MOV AH,0
INT 16H
MOV AX,4C00H
INT 21H
code ends
end start