15-110 PA9 Sample Solutions - Spring 2018

1.

def display(c, matrix):
# display current matrix of people on canvas c
    for row in range(0,len(matrix)):
        for col in range(0,len(matrix[row])):
            cell = matrix[row][col]
            if cell == 1:
                color = "yellow"
            else:
                color = "black"
            c.create_oval(25*col, 25*row, 25*col+25, 25*row+25,
                               fill=color, outline="black")

2.

def alive(matrix, row, col):
    return matrix[row][col] == 1

def dead(matrix, row, col):
    return matrix[row][col] == 0

def neighbors(matrix, row, col):
    # counts and returns number of live neighbors
    count = 0
    if row-1 >= 0 and col-1 >= 0 and alive(matrix, row-1, col-1):
        count = count + 1
    if row-1 >= 0 and alive(matrix, row-1, col):
        count = count + 1
    if row-1 >= 0 and col+1 < len(matrix[row]) and alive(matrix, row-1, col+1):
        count = count + 1
    if col-1 >= 0 and alive(matrix, row, col-1):
        count = count + 1
    if col+1 < len(matrix[row]) and alive(matrix, row, col+1):
        count = count + 1
    if row+1 < len(matrix) and col-1 >= 0 and alive(matrix, row+1, col-1):
        count = count + 1
    if row+1 < len(matrix) and alive(matrix, row+1, col):
        count = count + 1
    if row+1 < len(matrix) and col+1 < len(matrix[row]) and 
                               alive(matrix, row+1, col+1):
        count = count + 1
    return count

3.

def nextsecond(matrix):
    newmatrix = []
    for i in range(len(matrix)):
        row = len(matrix[i]) * [0]
        newmatrix.append(row)
    for row in range(len(matrix)):
        for col in range(len(matrix[row])):
            count = neighbors(matrix, row, col)
            if alive(matrix, row, col):
                #underpopulation - death
                if count < 2:
                    newmatrix[row][col] = 0
                #overpopulation - death
                elif count > 3:
                    newmatrix[row][col] = 0
                #survival
                else:
                    newmatrix[row][col] = 1
            else:
                if count == 3:
                    newmatrix[row][col] = 1
                else:
                    newmatrix[row][col] = 0
    return newmatrix

4.

def create_matrix(p):
    matrix = []
    for i in range(0,30):
        row = []
        for j in range(0,40):
            if randint(0,99) < p:
                row.append(1)
            else:
                row.append(0)
        matrix.append(row)
    return matrix

def run_simulation2(init_seed, num_seconds, p):
    # create a canvas of size 1000 X 750
    window = Tk()
    c = Canvas(window, width=1000, height=750)
    c.pack()
    seed(init_seed)
    matrix = create_matrix(p)
    display(c, matrix)
    c.update()
    sleep(2)
    for i in range(num_seconds):
        matrix = nextsecond(matrix)
        display(c, matrix)
        c.update()
        sleep(2)
    window.mainloop()    # wait until user clicks close button
    return matrix