【笔记】Stanford OpenCourse—CS106A：Programming Methodology—005
ch04 Programming Exercise
1.
1
/**
2
* File: Ex4_1.java
3
* ----------------
4
* This program is to generate the lyrics .
5
*
6
*
@author
Administrator
7
*
8
*/
9
import
acm.program.
*
;
10
11
public
class
Ex4_1
extends
ConsoleProgram {
12
13
public
void
run() {
14
15
for
(
int
i
=
n; i
>
0
; i
--
){
16
println(i
+
"
bottles of beer on the wall.
"
);
17
println(i
+
"
bottles of beer.
"
);
18
println(
"
You take one down, pass it around.
"
);
19
println(i
-
1
+
"
bottles of beer on the wall.
"
);
20
println();
21
}
22
23
}
24
25
private
static
final
int
n
=
99
;
26
27
28
}
2.
1
/**
2
* File: Ex4_2.java
3
* ----------------
4
* This program also write a silly song.
5
*
6
*
@author
Administrator
7
*
8
*/
9
10
import
acm.program.
*
;
11
12
public
class
Ex4_2
extends
ConsoleProgram {
13
14
public
void
run() {
15
16
for
(
int
i
=
1
; i
<
11
; i
++
) {
17
println(
"
This old man, he played
"
+
i
+
"
.
"
);
18
println(
"
He played knick-knack on my
"
);
19
switch
(i){
20
case
1
: println(
"
thumb
"
);
break
;
21
case
2
: println(
"
shoe
"
);
break
;
22
case
3
: println(
"
knee
"
);
break
;
23
case
4
: println(
"
door
"
);
break
;
24
case
5
: println(
"
hive
"
);
break
;
25
case
6
: println(
"
sticks
"
);
break
;
26
case
7
: println(
"
up to heaven
"
);
break
;
27
case
8
: println(
"
pate
"
);
break
;
28
case
9
: println(
"
spine
"
);
break
;
29
case
10
: println(
"
shin
"
);
break
;
30
default
:
break
;
31
}
32
33
println(
"
With a knick-knack, paddy-whack.
"
);
34
println(
"
Give you dog a bone.
"
);
35
println(
"
This old man came roling home.
"
);
36
println();
37
38
}
39
}
40
41
42
}
3.
1
/**
2
* File: Ex4_3.java
3
* ----------------
4
* This program reads in a positive integer N and then calculates and
5
* displays the sum of the first N odd integers.
6
*
7
*
@author
Administrator
8
*
9
*/
10
11
import
acm.program.
*
;
12
13
public
class
Ex4_3
extends
ConsoleProgram {
14
15
public
void
run() {
16
17
int
sum
=
0
;
18
int
n
=
1
;
19
20
int
N
=
readInt(
"
Enter N:
"
);
21
for
(
int
i
=
0
; i
<
N; i
++
) {
22
sum
+=
n;
23
n
+=
2
;
24
}
25
println(
"
sum =
"
+
sum);
26
27
}
28
29
}
4.略。
5.
1
/**
2
* File: Ex4_5.java
3
* ----------------
4
* This program display the integers between 1 and 100 that are
5
* divisible by either 6 or 7 but not both.
6
*
7
*
@author
Administrator
8
*
9
*/
10
11
import
acm.program.
*
;
12
13
public
class
Ex4_4
extends
ConsoleProgram {
14
15
public
void
run() {
16
for
(
int
i
=
1
; i
<=
100
; i
++
){
17
18
if
((i
%
6
==
0
||
i
%
7
==
0
)
&&
(i
%
42
!=
0
)){
19
println(i);
20
}
21
}
22
}
23
24
}
6.略。
7.
1
/**
2
* File: Ex4_7.java
3
* ----------------
4
* This program reverse the order of the integer.
5
*
6
*
@author
Administrator
7
*
8
*/
9
10
import
acm.program.
*
;
11
12
public
class
Ex4_7
extends
ConsoleProgram {
13
14
public
void
run() {
15
println(
"
This program reverse the digits in an intger.
"
);
16
int
n
=
readInt(
"
Enter a positive integer:
"
);
17
int
rn
=
0
;
18
while
(n
>
0
){
19
rn
=
rn
*
10
+
n
%
10
;
20
n
/=
10
;
21
}
22
println(
"
The reversed number is
"
+
rn);
23
}
24
25
}
8.
1
/**
2
* File: Ex4_8.java
3
* ----------------
4
* This program counts backwards from the value START
5
* to zero, as in the countdown preceding a rocket
6
* launch.
7
*
8
*
@author
Administrator
9
*
10
*/
11
12
import
acm.program.
*
;
13
14
public
class
Ex4_8
extends
ConsoleProgram {
15
16
private
static
final
int
START
=
10
;
17
18
public
void
run() {
19
int
t
=
START;
20
while
( t
>=
0
){
21
println(t);
22
t
--
;
23
}
24
println(
"
Liftoff!
"
);
25
}
26
27
}
9.
1
/**
2
* File: Ex4_9.java
3
* ----------------
4
* Fibonacci sequence.
5
*
6
*
@author
Administrator
7
*
8
*/
9
10
import
acm.program.
*
;
11
12
public
class
Ex4_9
extends
ConsoleProgram {
13
14
public
void
run(){
15
16
int
n1
=
0
;
17
int
n2
=
1
;
18
int
n
=
0
;
19
int
i
=
2
;
20
21
println(
"
F0 =
"
+
n1);
22
println(
"
F1 =
"
+
n2);
23
24
while
(n
<
10000
){
25
n
=
n1
+
n2;
26
println(
"
F
"
+
i
+
"
=
"
+
n);
27
n1
=
n2; //Fn = Fn-1 + Fn-2
28
n2
=
n;
29
i
++
;
30
}
31
32
}
33
34
}
10.略
11. 这里要画个8x8的棋盘，方格放置简单，放圆有点困难，看图总结，啥时候放圆。
1
/**
2
* File: Ex4_11.java
3
* -----------------
4
* checkboard
5
*
6
*
@author
Administrator
7
*
8
*/
9
import
acm.graphics.
*
;
10
import
acm.program.
*
;
11
12
public
class
Ex4_11
extends
GraphicsProgram {
13
public
void
run(){
14
for
(
int
i
=
0
; i
<
8
; i
++
){
15
for
(
int
j
=
0
; j
<
8
; j
++
){
16
add(
new
GRect(i
*
20
, j
*
20
,
20
,
20
));
17
if
(((j
%
2
==
0
)
&&
(i
%
2
!=
0
))
||
((j
%
2
!=
0
)
&&
(i
%
2
==
0
))){
18
add(
new
GOval(i
*
20
, j
*
20
,
20
,
20
));
19
20
}
21
}
22
}
23
24
}
25
26
}
12. 简单的日历，画表简单，就是放格子，加数字有点困难。
1
/**
2
* File: Ex4_12.java
3
* -----------------
4
* calendar.
5
*
6
*
@author
Administrator
7
*
8
*/
9
import
acm.graphics.
*
;
10
import
acm.program.
*
;
11
12
public
class
Ex4_12
extends
GraphicsProgram {
13
public
void
run() {
14
int
rows
=
(DAYS_IN_MONTH
+
DAY_MONTH_STARTS)
/
7
;
15
if
((DAY_MONTH_STARTS
+
DAYS_IN_MONTH)
%
7
!=
0
){
16
rows
++
;
17
}
18
19
for
(
int
i
=
0
; i
<
rows; i
++
) {
20
int
y
=
i
*
DAY_HEIGHT;
21
22
for
(
int
j
=
0
; j
<
7
; j
++
) {
23
int
x
=
j
*
DAY_WIDTH;
24
25
add(
new
GRect(x, y, DAY_WIDTH, DAY_HEIGHT));
26
27
int
date
=
(((
7
*
i)
+
j)
-
DAY_MONTH_STARTS)
+
1
;
28
29
if
(date
>
0
&&
date
<=
DAYS_IN_MONTH) {
30
add(
new
GLabel(
""
+
date
+
"
.
"
, x
+
5
, y
+
15
));
31
}
32
33
}
34
}
35
}
36
37
//
The number of days in the month
38
private
static
final
int
DAYS_IN_MONTH
=
31
;
39
40
//
The day of the week on which the month starts
41
//
Sunday = 0, Monday = 1, ...
42
private
static
final
int
DAY_MONTH_STARTS
=
5
;
43
44
//
The width in pixels of a day on the calendar
45
private
static
final
int
DAY_WIDTH
=
40
;
46
47
//
The height in pixels of a day on the calendar
48
private
static
final
int
DAY_HEIGHT
=
30
;
49
50
51
}