AOC2021Day9.py

import pprint

heightMap = []
lowPoints = []

def getHeight(aRow, aCol, aDirection):
    if aDirection == 'N':
        if aRow == 0:
            return 99
        else:
            return heightMap[aRow - 1][aCol]
    elif aDirection == 'S':
        if aRow == len(heightMap) - 1:
            return 99
        else:
            return heightMap[aRow + 1][aCol]
    elif aDirection == 'E':
        if aCol == len(heightMap[0]) - 1:
            return 99
        else:
            return heightMap[aRow][aCol + 1]
    elif aDirection == 'W':
        if aCol == 0:
            return 99
        else:
            return heightMap[aRow][aCol - 1]
    else:
        assert False, 'This is embarrassing. How did I get here?'

    assert False, 'Should not be possible to get here'

def initHeightMap(aHeightMap):
    with open('scratch.txt') as INFILE:
        for LINE in INFILE:
            LINE = LINE.rstrip()
            row = [int(x) for x in list(LINE)]
            aHeightMap.append(row)

initHeightMap(heightMap)

for row in range(len(heightMap)):
    for col in range(len(heightMap[0])):
        n = getHeight(row, col, 'N')
        s = getHeight(row, col, 'S')
        e = getHeight(row, col, 'E')
        w = getHeight(row, col, 'W')

        currentHeight = heightMap[row][col]

        if currentHeight < n and currentHeight < s and currentHeight < e and currentHeight < w:
            lowPoints.append((row, col))

print(lowPoints)

sumRiskLevels = 0

for lowPoint in lowPoints:
    riskLevel = heightMap[lowPoint[0]][lowPoint[1]]
    riskLevel +=1
    sumRiskLevels += riskLevel

print(f'{sumRiskLevels=}')