Chapter 9 - Sonar

Source Code

sonar.py

1. # Sonar
3. import random
4. import sys
6. def drawBoard(board):
7.     hline = '    ' # initial space for the numbers down the left side of the board
8.     for i in range(1, 6):
9.         hline += (' ' * 9) + str(i)
11.     print hline
12.     print '   ' + ('0123456789' * 6)
13.     print
15.     for i in range(15):
16.         if i < 10:
17.             extraSpace = ' '
18.         else:
19.             extraSpace = ''
20.         print '%s%s %s %s' % (extraSpace, i, getRow(board, i), i)
22.     print
23.     print '   ' + ('0123456789' * 6)
24.     print hline
28. def getRow(board, row):
29.     boardRow = ''
30.     for i in range(60):
31.         boardRow += board[i][row]
32.     return boardRow
34. def getNewBoard():
35.     board = []
36.     for x in range(60):
37.         board.append([])
38.         for y in range(15):
39.             # use different characters for the ocean to make it more readable.
40.             if random.randint(0, 1) == 0:
41.                 ocean = '~'
42.             else:
43.                 ocean = '`'
44.             board[x].append(ocean)
45.     return board
47. def getRandomSubs(numSubs):
48.     subs = []
49.     for i in range(numSubs):
50.         subs.append([random.randint(0, 59), random.randint(0, 14)])
51.     return subs
53. def isValidMove(x, y):
54.     return x >= 0 and x <= 59 and y >= 0 and y <= 14
56. def makeMove(board, subs, x, y):
57.     if not isValidMove(x, y):
58.         return False
60.     smallestDistance = 100
61.     for s in subs:
62.         sx = s[0]
63.         sy = s[1]
65.         if abs(sx - x) < abs(sy - y):
66.             distance = abs(sy - y)
67.         else:
68.             distance = abs(sx - x)
70.         if distance < smallestDistance:
71.             smallestDistance = distance
73.     if smallestDistance == 0:
74.         # xy is directly on a sub!
75.         subs.remove([x, y])
76.         return 'You have found and destroyed a sub!'
77.     else:
78.         if smallestDistance < 10:
79.             board[x][y] = str(smallestDistance)
80.             return 'Sub detected at a distance of %s from the sonar device.' % (smallestDistance)
81.         else:
82.             board[x][y] = 'O'
83.             return 'Sonar did not detect anything. All subs out of range.'
84.             
86. def enterPlayerMove():
87.     print 'Where do you want to drop the next sonar device? (0-59 0-14) (or type quit)'
88.     while True:
89.         move = raw_input()
90.         if move.lower() == 'quit':
91.             print 'Thanks for playing!'
92.             sys.exit()
94.         move = move.split()
95.         if len(move) == 2 and move[0].isdigit() and move[1].isdigit() and isValidMove(int(move[0]), int(move[1])):
96.             return [int(move[0]), int(move[1])]
97.         print 'Enter a number from 0 to 59, a space, then a number from 0 to 14.'
100. def playAgain():
101.     # This function returns True if the player wants to play again, otherwise it returns False.
102.     print 'Do you want to play again? (yes or no)'
103.     return raw_input().lower().startswith('y')
106. def showInstructions():
107.     print '''Instructions:
108. You are the captain of a sub-hunting warship, USS Simon. Your current mission
109. is to find the three subs that are lurking in the part of the ocean you are in
110. and destroy them.
112. To play, enter the coordinates of the point in the ocean you wish to drop a
113. sonar device. The sonar can find out how far away the closest sub is to it.
114. For example, the d below marks where the device was dropped, and the 2's
115. represent distances of 2 away from the device. The 4's represent
116. distances of 4 away from the device.
118.     444444444
119.     4       4
120.     4 22222 4
121.     4 2   2 4
122.     4 2 d 2 4
123.     4 2   2 4
124.     4 22222 4
125.     4       4
126.     444444444
127. Press enter to continue...'''
128.     raw_input()
130.     print '''For example, here is a sub (the s) located a distance of 2 away from the
131. sonar device (the d):
133.     22222
134.     s   2
135.     2 d 2
136.     2   2
137.     22222
139. The point where the device was dropped will be marked with a 2.
141. The subs don't move around. They have shut off their engines and are "running
142. dark" to hide from you. Sonar devices can detect subs up to a distance of 9.
143. In that case, the point will be marked with O
145. If a device is directly dropped on a sub, you have discovered the location of
146. the sub, and it will be destroyed with depth charges. The sonar device will
147. remain there.
149. When you destroy a sub, all sonar devices will update to locate the next
150. closest sub.
151. Press enter to continue...'''
152.     raw_input()
153.     print
156. print 'S O N A R !'
157. print
158. print 'Would you like to view the instructions? (yes/no)'
159. if raw_input().lower().startswith('y'):
160.     showInstructions()
162. while True:
163.     sonarDevices = 16
164.     theBoard = getNewBoard()
165.     theSubs = getRandomSubs(3)
166.     drawBoard(theBoard)
167.     previousMoves = []
169.     while sonarDevices > 0:
170.         if sonarDevices > 1: extraSsonar = 's'
171.         else: extraSsonar = ''
172.         if len(theSubs) > 1: extraSsub = 's'
173.         else: extraSsub = ''
174.         print 'You have %s sonar device%s left. %s sub%s remaining.' % (sonarDevices, extraSsonar, len(theSubs), extraSsub)
176.         x, y = enterPlayerMove()
177.         previousMoves.append([x, y])
179.         moveResult = makeMove(theBoard, theSubs, x, y)
180.         if moveResult == False:
181.             continue
182.         else:
183.             if moveResult == 'You have found and destroyed a sub!':
184.                 # update all the sonar devices currently on the map.
185.                 for x, y in previousMoves:
186.                     makeMove(theBoard, theSubs, x, y)
187.             drawBoard(theBoard)
188.             print moveResult
192.         if len(theSubs) == 0:
193.             print 'You have destroyed all the subs! Congratulations and good game!'
194.             break
196.         sonarDevices -= 1
198.     if sonarDevices == 0:
199.         print 'We\'ve run out of sonar devices! Now we have to turn the ship around and head'
200.         print 'for home with the subs still out there! Game over.'
201.         print '    The remaining subs were here:'
202.         for s in theSubs:
203.             print '    %s, %s' % (s[0], s[1])
205.     if not playAgain():
206.         break

Code Explanation

1. # Sonar
3. import random
4. import sys

1. def drawBoard(board):
2.     hline = '    ' # initial space for the numbers down the left side of the board
3.     for i in range(1, 6):
4.         hline += (' ' * 9) + str(i)

1.     print hline
2.     print '   ' + ('0123456789' * 6)
3.     print

1.     for i in range(15):
2.         if i < 10:
3.             extraSpace = ' '
4.         else:
5.             extraSpace = ''
6.         print '%s%s %s %s' % (extraSpace, i, getRow(board, i), i)

1.     print
2.     print '   ' + ('0123456789' * 6)
3.     print hline

1. def getRow(board, row):
2.     boardRow = ''
3.     for i in range(60):
4.         boardRow += board[i][row]
5.     return boardRow

1. def getNewBoard():
2.     board = []
3.     for x in range(60):
4.         board.append([])

1.         for y in range(15):
2.             # use different characters for the ocean to make it more readable.
3.             if random.randint(0, 1) == 0:
4.                 ocean = '~'
5.             else:
6.                 ocean = '`'
7.             board[x].append(ocean)
8.     return board

1. def getRandomSubs(numSubs):
2.     subs = []
3.     for i in range(numSubs):
4.         subs.append([random.randint(0, 59), random.randint(0, 14)])
5.     return subs

1. def isValidMove(x, y):
2.     return x >= 0 and x <= 59 and y >= 0 and y <= 14

1. def makeMove(board, subs, x, y):
2.     if not isValidMove(x, y):
3.         return False
5.     smallestDistance = 100

1.     for s in subs:
2.         sx = s[0]
3.         sy = s[1]
5.         if abs(sx - x) < abs(sy - y):
6.             distance = abs(sy - y)
7.         else:
8.             distance = abs(sx - x)
10.         if distance < smallestDistance:
11.             smallestDistance = distance

1.     if smallestDistance == 0:
2.         # xy is directly on a sub!
3.         subs.remove([x, y])
4.         return 'You have found and destroyed a sub!'

1.     else:
2.         if smallestDistance < 10:
3.             board[x][y] = str(smallestDistance)
4.             return 'Sub detected at a distance of %s from the sonar device.' % (smallestDistance)

1.         else:
2.             board[x][y] = 'O'
3.             return 'Sonar did not detect anything. All subs out of range.'
4.             

1. def enterPlayerMove():
2.     print 'Where do you want to drop the next sonar device? (0-59 0-14) (or type quit)'
3.     while True:
4.         move = raw_input()
5.         if move.lower() == 'quit':
6.             print 'Thanks for playing!'
7.             sys.exit()

1.         move = move.split()
2.         if len(move) == 2 and move[0].isdigit() and move[1].isdigit() and isValidMove(int(move[0]), int(move[1])):
3.             return [int(move[0]), int(move[1])]
4.         print 'Enter a number from 0 to 59, a space, then a number from 0 to 14.'

1. def playAgain():
2.     # This function returns True if the player wants to play again, otherwise it returns False.
3.     print 'Do you want to play again? (yes or no)'
4.     return raw_input().lower().startswith('y')

1. def showInstructions():
2.     print '''Instructions:
3. You are the captain of a sub-hunting warship, USS Simon. Your current mission
4. is to find the three subs that are lurking in the part of the ocean you are in
5. and destroy them.
7. To play, enter the coordinates of the point in the ocean you wish to drop a
8. sonar device. The sonar can find out how far away the closest sub is to it.
9. For example, the d below marks where the device was dropped, and the 2's
10. represent distances of 2 away from the device. The 4's represent
11. distances of 4 away from the device.
13.     444444444
14.     4       4
15.     4 22222 4
16.     4 2   2 4
17.     4 2 d 2 4
18.     4 2   2 4
19.     4 22222 4
20.     4       4
21.     444444444
22. Press enter to continue...'''
23.     raw_input()

1.     print '''For example, here is a sub (the s) located a distance of 2 away from the
2. sonar device (the d):
4.     22222
5.     s   2
6.     2 d 2
7.     2   2
8.     22222
10. The point where the device was dropped will be marked with a 2.
12. The subs don't move around. They have shut off their engines and are "running
13. dark" to hide from you. Sonar devices can detect subs up to a distance of 9.
14. In that case, the point will be marked with O
16. If a device is directly dropped on a sub, you have discovered the location of
17. the sub, and it will be destroyed with depth charges. The sonar device will
18. remain there.
20. When you destroy a sub, all sonar devices will update to locate the next
21. closest sub.
22. Press enter to continue...'''
23.     raw_input()
24.     print

1. print 'S O N A R !'
2. print
3. print 'Would you like to view the instructions? (yes/no)'
4. if raw_input().lower().startswith('y'):
5.     showInstructions()

1. while True:
2.     sonarDevices = 16
3.     theBoard = getNewBoard()
4.     theSubs = getRandomSubs(3)
5.     drawBoard(theBoard)
6.     previousMoves = []

1.     while sonarDevices > 0:
2.         if sonarDevices > 1: extraSsonar = 's'
3.         else: extraSsonar = ''
4.         if len(theSubs) > 1: extraSsub = 's'
5.         else: extraSsub = ''
6.         print 'You have %s sonar device%s left. %s sub%s remaining.' % (sonarDevices, extraSsonar, len(theSubs), extraSsub)

1.         x, y = enterPlayerMove()
2.         previousMoves.append([x, y])

1.         moveResult = makeMove(theBoard, theSubs, x, y)
2.         if moveResult == False:
3.             continue

1.         else:
2.             if moveResult == 'You have found and destroyed a sub!':
3.                 # update all the sonar devices currently on the map.
4.                 for x, y in previousMoves:
5.                     makeMove(theBoard, theSubs, x, y)
6.             drawBoard(theBoard)
7.             print moveResult

1.         if len(theSubs) == 0:
2.             print 'You have destroyed all the subs! Congratulations and good game!'
3.             break

1.         sonarDevices -= 1

1.     if sonarDevices == 0:
2.         print 'We\'ve run out of sonar devices! Now we have to turn the ship around and head'
3.         print 'for home with the subs still out there! Game over.'
4.         print '    The remaining subs were here:'
5.         for s in theSubs:
6.             print '    %s, %s' % (s[0], s[1])

1.     if not playAgain():
2.         break

Things Covered In This Chapter: