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Day 11...ugly...

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Chris Pickett
2020-12-11 08:49:59 -06:00
parent 78e2ce126d
commit edc7fb1605
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Q11.cs Normal file
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using System;
using System.Diagnostics;
using System.IO;
namespace _2020
{
class Q11
{
static SeatState[,] list = null;
static int numRows = 0;
static int numCols = 0;
enum SeatState
{
Floor,
Empty,
Occupied,
}
public static void Go()
{
var start = DateTime.Now;
MakeList();
Debug.WriteLine($"Q11 MakeList took {(DateTime.Now - start).TotalMilliseconds}ms");
var p1start = DateTime.Now;
Part1();
Debug.WriteLine($"Q11 part1 took {(DateTime.Now - p1start).TotalMilliseconds}ms");
var p2start = DateTime.Now;
Part2();
Debug.WriteLine($"Q11 part2 took {(DateTime.Now - p2start).TotalMilliseconds}ms");
Debug.WriteLine($"Q11 took {(DateTime.Now - start).TotalMilliseconds}ms");
}
static void MakeList()
{
var lines = File.ReadAllLines("11input.txt");
numRows = lines.Length;
numCols = lines[0].Length;
list = new SeatState[numRows, numCols];
for (int i = 0; i < numRows; i++)
{
for (int j = 0; j < numCols; j++)
{
list[i, j] = lines[i][j] == '.' ? SeatState.Floor : SeatState.Empty;
}
}
}
static int GetNumOccupiedAdjacent(SeatState[,] seatList, int row, int col)
{
int numOccupied = 0;
if (row - 1 >= 0)
{
if (col - 1 >= 0 && seatList[row - 1, col - 1] == SeatState.Occupied)
{
numOccupied++;
}
if (seatList[row - 1, col] == SeatState.Occupied)
{
numOccupied++;
}
if (col + 1 < numCols && seatList[row - 1, col + 1] == SeatState.Occupied)
{
numOccupied++;
}
}
if (col - 1 >= 0 && seatList[row, col - 1] == SeatState.Occupied)
{
numOccupied++;
}
if (col + 1 < numCols && seatList[row, col + 1] == SeatState.Occupied)
{
numOccupied++;
}
if (row + 1 < numRows)
{
if (col - 1 >= 0 && seatList[row + 1, col - 1] == SeatState.Occupied)
{
numOccupied++;
}
if (seatList[row + 1, col] == SeatState.Occupied)
{
numOccupied++;
}
if (col + 1 < numCols && seatList[row + 1, col + 1] == SeatState.Occupied)
{
numOccupied++;
}
}
return numOccupied;
}
static int GetNumOccupiedLOS(SeatState[,] seatList, int row, int col)
{
int numOccupied = 0;
Func<int, int, bool> checkSeat = (checkRow, checkCol) =>
{
if (seatList[checkRow, checkCol] == SeatState.Occupied)
{
numOccupied++;
return true;
}
if (seatList[checkRow, checkCol] == SeatState.Empty)
{
return true;
}
return false;
};
// ul
for (int checkRow = row - 1, checkCol = col - 1; checkRow >= 0 && checkCol >= 0; checkRow--, checkCol--)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// u
for (int checkRow = row - 1, checkCol = col; checkRow >= 0; checkRow--)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// ur
for (int checkRow = row - 1, checkCol = col + 1; checkRow >= 0 && checkCol < numCols; checkRow--, checkCol++)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// l
for (int checkRow = row, checkCol = col - 1; checkCol >= 0; checkCol--)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// r
for (int checkRow = row, checkCol = col + 1; checkCol < numCols; checkCol++)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// dl
for (int checkRow = row + 1, checkCol = col - 1; checkRow < numRows && checkCol >= 0; checkRow++, checkCol--)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// d
for (int checkRow = row + 1, checkCol = col; checkRow < numRows; checkRow++)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
// dr
for (int checkRow = row + 1, checkCol = col + 1; checkRow < numRows && checkCol < numCols; checkRow++, checkCol++)
{
if (checkSeat(checkRow, checkCol))
{
break;
}
}
return numOccupied;
}
static void Part1()
{
SeatState[,] currState = new SeatState[numRows, numCols];
SeatState[,] nextState = new SeatState[numRows, numCols];
Array.Copy(list, currState, numRows * numCols);
int rounds = 0;
int totalNumOccupied = 0;
for (int numChanges = 0; rounds == 0 || numChanges != 0; rounds++)
{
Array.Copy(currState, nextState, numRows * numCols);
totalNumOccupied = 0;
numChanges = 0;
for (int i = 0; i < numRows; i++)
{
for (int j = 0; j < numCols; j++)
{
var numOccupied = GetNumOccupiedAdjacent(currState, i, j);
if (currState[i, j] == SeatState.Empty && numOccupied == 0)
{
nextState[i, j] = SeatState.Occupied;
numChanges++;
}
else if (currState[i, j] == SeatState.Occupied && numOccupied >= 4)
{
nextState[i, j] = SeatState.Empty;
numChanges++;
}
if (nextState[i, j] == SeatState.Occupied)
{
totalNumOccupied++;
}
}
}
Array.Copy(nextState, currState, numRows * numCols);
}
Debug.WriteLine($"Q11Part1: stabilized after {rounds - 1} rounds, total occupied={totalNumOccupied}");
}
static void Part2()
{
SeatState[,] currState = new SeatState[numRows, numCols];
SeatState[,] nextState = new SeatState[numRows, numCols];
Array.Copy(list, currState, numRows * numCols);
int rounds = 0;
int totalNumOccupied = 0;
for (int numChanges = 0; rounds == 0 || numChanges != 0; rounds++)
{
Array.Copy(currState, nextState, numRows * numCols);
totalNumOccupied = 0;
numChanges = 0;
for (int i = 0; i < numRows; i++)
{
for (int j = 0; j < numCols; j++)
{
var numOccupied = GetNumOccupiedLOS(currState, i, j);
if (currState[i, j] == SeatState.Empty && numOccupied == 0)
{
nextState[i, j] = SeatState.Occupied;
numChanges++;
}
else if (currState[i, j] == SeatState.Occupied && numOccupied >= 5)
{
nextState[i, j] = SeatState.Empty;
numChanges++;
}
if (nextState[i, j] == SeatState.Occupied)
{
totalNumOccupied++;
}
}
}
Array.Copy(nextState, currState, numRows * numCols);
}
Debug.WriteLine($"Q11Part2: stabilized after {rounds - 1} rounds, total occupied={totalNumOccupied}");
}
}
}