#ProjectEuler/Python/Problem28.py
#Matthew Ellison
# Created: 09-22-19
#Modified: 09-22-19
#What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral
#Unless otherwise listed, all of my non-standard imports can be gotten from my pyClasses repository at https://bitbucket.org/Mattrixwv/pyClasses
"""
	Copyright (C) 2019  Matthew Ellison

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""


from Stopwatch import Stopwatch


def setupGrid() -> list:
	#Setup the grid to be the right size and fill it with 0's
	grid = [[0 for x in range(1001)] for y in range(1001)]

	finalLocation = False	#A flag to indicate if the final location to be filled has been reached
	currentNum = 1	#Set the number that is going to be put at each location
	#Start with the middle location and set it correctly and advance the tracker to the next number
	xLocation = 500
	yLocation = 500
	grid[yLocation][xLocation] = currentNum
	currentNum += 1
	#Move right the first time
	xLocation += 1
	#Move in a circular pattern until you reach the final location
	while(not finalLocation):
		#Move down until you reach a blank location on the left
		while(grid[yLocation][xLocation - 1] != 0):
			grid[yLocation][xLocation] = currentNum
			currentNum += 1
			yLocation += 1

		#Move left until you reach a blank location above
		while(grid[yLocation - 1][xLocation] != 0):
			grid[yLocation][xLocation] = currentNum
			currentNum += 1
			xLocation -= 1

		#Move up until you reach a blank location to the right
		while(grid[yLocation][xLocation + 1] != 0):
			grid[yLocation][xLocation] = currentNum
			currentNum += 1
			yLocation -= 1

		#Move right until you reach a blank location below
		while(grid[yLocation + 1][xLocation] != 0):
			grid[yLocation][xLocation] = currentNum
			currentNum += 1
			xLocation += 1
			#Check if you are at the final location and break the loop if you are
			if(xLocation == len(grid)):
				finalLocation = True
				break
	return grid

def findSum(grid: list) -> int:
	sumOfDiagonals = 0
	leftSide = 0
	rightSide = len(grid) - 1
	row = 0
	while(row < len(grid)):
		#This ensure the middle location is only counted once
		if(leftSide == rightSide):
			sumOfDiagonals += grid[row][leftSide]
		else:
			sumOfDiagonals += grid[row][leftSide]
			sumOfDiagonals += grid[row][rightSide]
		row += 1
		leftSide += 1
		rightSide -= 1
	return sumOfDiagonals

def Problem28():
	#Setup the grid
	grid = setupGrid()
	#Find the sum of the diagonals in the grid
	diagSum = findSum(grid)

	#Print the results
	print("The sum of the diagonals in the given grid is " + str(diagSum))

#This calls the appropriate functions if the script is called stand alone
if __name__ == "__main__":
	timer = Stopwatch()
	timer.start()
	Problem28()
	timer.stop()
	print("It took " + timer.getString() + " to run this algorithm")

""" Results:
The sum of the diagonals in the given grid is 669171001
It took 197.764 milliseconds to run this algorithm
"""