Python IDE by 101Computing.net

#Frog Puzzle Challenge - 101computing.net/frog-puzzle-challenge
import turtle, time

GREEN = 1
RED = -1
EMPTY = 0
SPEED = 0.1 # Choose a value between 0 and 1

myPen = turtle.Turtle()
myPen.tracer(0)
myPen.speed(0)
myPen.hideturtle()
screen = turtle.Screen()
screen.bgcolor("#0398fc")
myPen.pensize(2)
myPen.penup()

#Draw a frog (with two eyes!) at a given position (x,y coordinates)
def drawFrog(color,x,y):
  myPen.goto(x,y)
  myPen.fillcolor(color)
  myPen.begin_fill()
  myPen.circle(10)
  myPen.end_fill()
  myPen.goto(x-8,y+15)
  myPen.fillcolor("white")
  myPen.begin_fill()
  myPen.circle(4)
  myPen.end_fill()
  myPen.goto(x+8,y+15)
  myPen.fillcolor("white")
  myPen.begin_fill()
  myPen.circle(4)
  myPen.end_fill()
  myPen.goto(x-8,y+17)
  myPen.fillcolor("black")
  myPen.begin_fill()
  myPen.circle(2)
  myPen.end_fill()  
  myPen.goto(x+8,y+17)
  myPen.fillcolor("black")
  myPen.begin_fill()
  myPen.circle(2)
  myPen.end_fill()

#Draw a ripple effect around a waterlily to show where a frog jumped to
def drawRipple(color,x,y):
  myPen.goto(x,y-5)
  myPen.pendown()
  myPen.color(color)
  myPen.circle(25)
  myPen.penup()

#Write text in the middle of the screen
def writeText(color,text):
  style = ('Courier', 20, 'italic')
  myPen.color(color)
  myPen.penup()
  myPen.goto(0,0)
  myPen.pendown()
  myPen.write(text, font=style, align='center')               
  myPen.penup()

#Draw the pond, all 13 waterlilies and all the green and red frogs
def drawPond():
  myPen.clear()
  
  for i in range(0,len(waterlilies)):
    xy=coordinates[i]
    
    myPen.goto(xy[0],xy[1])
    myPen.fillcolor("green")
    myPen.begin_fill()
    myPen.circle(20)
    myPen.end_fill()
    
    frog = waterlilies[i]
    if frog==GREEN:
      drawFrog("#00e304",xy[0],xy[1]+10)
    elif frog==RED:  
      drawFrog("#f51820",xy[0],xy[1]+10)
    
   
#Check if there is only one red frog left (Puzzle solved?)
def checkPond():
  total = 0
  for value in waterlilies:
    total += value
  return total==-1   #True if only the red frog is left, False otherwise

#The graph representing all the potential jumps a frog can do
pond = {0:[[2,1],[6,3],[10,5]],
        1:[[5,3],[11,6],[7,4]],
        2:[[0,1],[6,4],[12,7]],
        3:[[9,6]],
        4:[[8,6]],
        5:[[1,3],[7,6],[11,8]],
        6:[[0,3],[2,4],[12,9],[10,8]],
        7:[[1,4],[5,6],[11,9]],
        8:[[4,6]],
        9:[[3,6]],
        10:[[0,5],[6,8],[12,11]],
        11:[[5,8],[1,6],[7,9]],
        12:[[10,11],[6,9],[2,7]]
}

#The initial position of GREEN and RED frogs on the pond. (13 waterlilies)
waterlilies = [GREEN,GREEN,EMPTY,EMPTY,GREEN,GREEN,EMPTY,GREEN,GREEN,EMPTY,EMPTY,RED,EMPTY]

#The coordinates of all 13 waterlilies...
coordinates = [(-150,140),(0,140),(150,140),
                  (-75,70),(75,70),
                (-150,0),(0,0),(150,0),
                  (-75,-70),(75,-70),
                (-150,-140),(0,-140),(150,-140)]

drawPond()
myPen.getscreen().update() 
time.sleep(3)

#A backtracking algorithm based on a recursive function to try to solve this puzzle!
def jumpAround():
  for key in pond:
    if waterlilies[key] != 0:
      #There is a frog on this waterlily!
      jumps = pond[key]
      for jump in jumps:
        if waterlilies[jump[0]]==0 and waterlilies[jump[1]]>0:
          #It is possibe to jump on this edge of the graph! so let's jump...
          waterlilies[jump[0]]=waterlilies[key]
          waterlilies[key] = 0
          waterlilies[jump[1]] = 0
          drawPond()
          drawRipple("lightblue",coordinates[jump[0]][0],coordinates[jump[0]][1])
          myPen.getscreen().update() 
          time.sleep(1-SPEED)

if checkPond():
            #We have a solution!
            steps.append(str(key) + " -> " + str(jump[0]) )
            return True
          else:
            #Recursive call!
            if jumpAround():
              steps.insert(0,str(key) + " -> " + str(jump[0]) )
              return True
            else:
              #Cancel move before checking the next possible move
              waterlilies[key]=waterlilies[jump[0]]
              waterlilies[jump[0]] = 0
              waterlilies[jump[1]] = GREEN
              drawPond()
              drawRipple("red",coordinates[key][0],coordinates[key][1])
              drawRipple("red",coordinates[jump[1]][0],coordinates[jump[1]][1])
              writeText("black","Backtrack!")
              myPen.getscreen().update() 
              time.sleep(1-SPEED)
              drawPond()
              myPen.getscreen().update() 
              time.sleep(1-SPEED)
              
  #After trying every potential move, no solution was found!        
  return False

#Final output!
steps = []
if jumpAround():
  print("Puzzle solved!")
  writeText("black","Puzzle Solved!") 
  print("Steps / Hops: ")
  print("\n".join(steps))
  myPen.getscreen().update() 
else:
  print("This puzzle cannot be solved!")
  writeText("black","This puzzle cannot be solved!") 
  myPen.getscreen().update()

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