Lab 4: Solutions
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Table of Contents
Lab 4.1 Solutions
Inverse Triangle
This solution is simple because it uses the loop command.
Simple inverse triangle
1 ; Start instructions
2 ; ---------------------------------------------
3 ; Register information
4 ; EAX: ; temp var, the character to print
5 ; EBX: ; column counter (inner loop)
6 ; ECX: ; row counter (outer loop)
7 ; EDX: ; not used
8 ; ---------------------------------------------
9 mov ecx, 5 ; ECX is i (this must be ECX for 'loop' instruction)
10outer:
11 mov ebx, 0 ; reset j
12 inner_start:
13 cmp ebx, ecx ; compare j and i
14 jge inner_end ; if (j => i) exit inner loop
15 inc ebx ; j++
16 mov eax, ebx ; print the counter (or mov a DX label here)
17 call print_int ; Print j
18 jmp inner_start ; continue inner loop
19 inner_end:
20 call print_nl
21 loop outer ; if EXC != 0, continue outer loop
22 ; End instructions, clean up
Expected Output
12345
1234
123
12
1
Right Triangle
Right triangle
1 ; Start instructions
2 ; ---------------------------------------------
3 ; Register information
4 ; EAX: ; column loop counter; the character to print
5 ; EBX: ; row loop control variable
6 ; ECX: ; row loop counter
7 ; EDX: ; column loop control variable
8 ; ---------------------------------------------
9
10 mov ecx, 0 ; ECX is i, row counter
11 mov ebx, 5 ; ebx loop condition (number of rows)
12row:
13 cmp ecx, ebx ; compare i and number of rows
14 jg row_end ; if (i > rows) exit loop
15
16 ; equilateral triangle
17 mov edx, ecx ; set column control var equal to the row
18
19 mov eax, 0 ; reset column counter
20 call column ; print the column data
21 call print_nl
22 inc ecx ; i++
23 jmp row ; goto row start
24row_end:
25 jmp end ; all done
26
27; print the column data
28column:
29 cmp eax, edx ; compare j and i
30 jge return ; if (j => i) call "ret"
31 inc eax ; j++
32 call print_int ; Print loop counter in EAX
33 jmp column ; continue column loop
34
35return:
36 ret ; return to the last address called
37
38end:
39 ; End instructions, clean up
Expected Output
1
12
123
1234
12345
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Lab 4.2 Solutions
Wide Triangle
1 ; Start instructions
2 ; ---------------------------------------------
3 ; Register information
4 ; EAX: ; column loop counter; the character to print
5 ; EBX: ; row loop control variable
6 ; ECX: ; row loop counter
7 ; EDX: ; column loop control variable
8 ; ---------------------------------------------
9
10 mov ecx, 0 ; ECX is i, row counter
11 mov ebx, 5 ; ebx loop condition (number of rows)
12row:
13 cmp ecx, ebx ; compare i and number of rows
14 jg row_end ; if (i > rows) exit loop
15
16 ; wide triangle
17 mov eax, 3 ; multiplication factor
18 mul ecx ; multiple the factor (EAX) by the loop counter in ECX
19 ; to print a wide triangle
20 mov edx, eax ; put the number of columns to print in EDX
21
22 mov eax, 0 ; reset column counter
23 call column ; print the column data
24 call print_nl
25 inc ecx ; i++
26 jmp row ; goto row start
27row_end:
28 jmp end ; all done
29
30; print the column data
31column:
32 cmp eax, edx ; compare j and i
33 jge return ; if (j => i) call "ret"
34 inc eax ; j++
35 push eax ; save counter
36 mov eax, char ; get character to print
37 call print_string ; Print *
38 pop eax ; restore counter
39 jmp column ; continue column loop
40
41return:
42 ret ; return to the last address called
43
44end:
45 ; End instructions, clean up
Wide Triangle Expected Results (i * 3)
1*
2* * * *
3* * * * * * *
4* * * * * * * * * *
5* * * * * * * * * * * * *
6* * * * * * * * * * * * * * * *
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Lab 4.3 Solutions
Square Curve
1 ; Start instructions
2 ; ---------------------------------------------
3 ; Register information
4 ; EAX: ; column loop counter; the character to print
5 ; EBX: ; row loop control variable
6 ; ECX: ; row loop counter
7 ; EDX: ; column loop control variable
8 ; ---------------------------------------------
9
10 mov ecx, 0 ; ECX is i, row counter
11 mov ebx, 6 ; ebx loop condition (number of rows)
12row:
13 cmp ecx, ebx ; compare i and number of rows
14 jg row_end ; if (i > rows) exit loop
15
16 ; Square curve
17 mov eax, ecx ; Get the row
18 mul ecx ; EAX = row*row
19 mov edx, eax ; put the number of columns to print in EDX
20
21 mov eax, 0 ; reset column counter
22 call column ; print the column data
23 call print_nl
24 inc ecx ; i++
25 jmp row ; goto row start
26row_end:
27 jmp end ; all done
28
29; print the column data
30column:
31 cmp eax, edx ; compare j and i
32 jg return ; if (j => i) call "ret"
33 inc eax ; j++
34 push eax ; save counter
35 mov eax, char ; get character to print
36 call print_string ; Print *
37 pop eax ; restore counter
38 jmp column ; continue column loop
39
40return:
41 ret ; return to the last address called
42
43end:
44 ; End instructions, clean up
Square curve (n * n) Expected Results
1*
2* *
3* * * * *
4* * * * * * * * * *
5* * * * * * * * * * * * * * * * *
6* * * * * * * * * * * * * * * * * * * * * * * * * *
7* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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Lab 4.4 Solutions
Skinny Triangle
1 ; Start instructions
2 ; ---------------------------------------------
3 ; Register information
4 ; EAX: ; column loop counter; the character to print
5 ; EBX: ; row loop control variable
6 ; ECX: ; row loop counter
7 ; EDX: ; column loop control variable
8 ; ---------------------------------------------
9
10 mov ecx, 1 ; ECX is i, row counter
11 mov ebx, 21 ; ebx loop condition (number of rows)
12row:
13 cmp ecx, ebx ; compare i and number of rows
14 jg row_end ; if (i > rows) exit loop
15
16 ;
17 ; skinny triangle ** ECX must start at 1, not 0. **
18 ; EAX = EAX/ECX; columns = rows/x
19 mov eax, ecx ; move the current row value into EAX
20 push ecx ; save current row value
21 mov ecx, 5 ; put our divisor in ECX
22 mov edx, 0 ; initialize the EDX (where the remainder goes)
23 div ecx ; EAX = EAX / ECX
24 mov edx, eax ; put the number of columns to print in EDX
25 pop ecx ; restore the row value to ECX
26 ;
27 mov eax, 0 ; reset column counter
28 call column ; print the column data
29 call print_nl
30 inc ecx ; i++
31 jmp row ; start new row
32row_end:
33 jmp end ; all done
34
35; print the column data
36column:
37 cmp eax, edx ; compare j and i
38 jg return ; if (j => i) call "ret"
39 inc eax ; j++
40 push eax ; save counter
41 mov eax, char ; get character to print
42 call print_string ; Print *
43 pop eax ; restore counter
44 jmp column ; continue column loop
45
46return:
47 ret ; return to the last address called
48
49end:
50 ; End instructions, clean up
The Burj Khalifa! n/5
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