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Day 5

Hydrothermal Venture

view the Advent of Code 2021 Day 5 challenge

Setup

# Setup - load any packages
import pandas as pd
import numpy as np

Load the data

#read the data into a pandas dataframe
def LoadData(filename):
    return pd.read_csv(filename,
        #seperators are " -> " or ","
        sep=" -> |,",
        names=['x1', 'y1', 'x2', 'y2'], 
        header=None, 
        engine="python")

def CreateGrid(x,y):
    return np.zeros((x,y), dtype=int)

# load the data
day5_lines=LoadData("day5_data.txt")

# get the minimum and maximum values
print(f'min = {day5_lines.min().min()} max = {day5_lines.max().max()}')

min = 10 max = 989

Part 1

def MapVents (data, grid, part1=True):
    #loop through each row in the 
    for index, row in data.iterrows():
        if HoriOrVert(row):
            #process 
            grid=PlotLine(row, grid)
        else:
            #process all lines
            if part1==False:
                grid=PlotDiagonalLine(row, grid)
            
    #Calculate the total number of overlaping cells
    count=CountOverlaps(grid)
    #return the result
    return count

def HoriOrVert(row):
    #Return true if the line is horizontal or vertical i.e X1/2 or Y1/2 values are the same
    if row["x1"]==row["x2"] or row["y1"]==row["y2"] :
        return True
    else:
        return False
    
def CountOverlaps(grid):
    # Count the number of values greater than 1
    return sum(sum(grid>1))

def PlotLine(row, grid):
    # Add the line to the grid
    for i in range(min(row["x1"], row["x2"]),max(row["x1"],row["x2"])+1):
        for c in range(min(row["y1"], row["y2"]),max(row["y1"],row["y2"])+1):
            grid[i][c]=grid[i][c]+1
    # Return the updated grid
    return grid

def PlotDiagonalLine(row, grid):
    # determine the direction
    if (((row["x1"] < row["x2"]) and (row["y1"] < row["y2"]) or (row["x1"] > row["x2"]) and (row["y1"] > row["y2"]))):
        #diagonal up
        #Set starting x and y values
        x=min(row["x1"], row["x2"])
        y=min(row["y1"], row["y2"])
        for i in range((max(row["x1"],row["x2"])-min(row["x1"], row["x2"]))+1):
            # increase the cell value by 1
            grid[x][y]=grid[x][y]+1
            # increase x and y coordinates
            x = x + 1
            y = y + 1
    else:
        # diagonal down
        # Set starting x and y values
        x=min(row["x1"], row["x2"])
        # use maximum for diagonal downward lines
        y=max(row["y1"], row["y2"])
        
        for i in range((max(row["x1"],row["x2"])-min(row["x1"], row["x2"]))+1):
            # increase the cell value by 1
            grid[x][y]=grid[x][y]+1
            # increase x and decrease y coordinates
            x = x + 1
            y = y - 1
    # Return the updated grid
    return grid

# load the data
day5_lines=LoadData("day5_data.txt")

# get the minimum and maximum values
print(f'min = {day5_lines.min().min()} max = {day5_lines.max().max()}')

# create a 1000x1000 numpy array to store the lines
grid=CreateGrid(1000,1000)

p1_answer=MapVents(day5_lines, grid, True)

print(f'answer = {p1_answer}')

min = 10 max = 989
answer = 5698

Part 2

view the Advent of Code 2021 Day 5 challenge Part 2

# load the data
day5_lines=LoadData("day5_data.txt")

# get the minimum and maximum values
print(f'min = {day5_lines.min().min()} max = {day5_lines.max().max()}')

# create a 1000x1000 numpy array to store the lines
grid=CreateGrid(1000,1000)

p2_answer=MapVents(day5_lines, grid, False)

print(f'answer = {p2_answer}')

min = 10 max = 989
answer = 15463