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2-3x perf improvement for fun

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The adjacent checking functions are still embarrassing, though...
This commit is contained in:
Chris Pickett
2020-12-11 09:34:46 -06:00
parent ac23dd44bf
commit aa8d9b5fdb
1 changed files with 28 additions and 24 deletions
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52
Q11.cs
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@ -1,6 +1,8 @@
using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
namespace _2020
{
@ -189,6 +191,22 @@ namespace _2020
return numOccupied;
}
static int GetNumOccupied(SeatState[,] currState)
{
int totalNumOccupied = 0;
for (int i = 0; i < numRows; i++)
{
for (int j = 0; j < numCols; j++)
{
if (currState[i, j] == SeatState.Occupied)
{
totalNumOccupied++;
}
}
}
return totalNumOccupied;
}
static void Part1()
{
SeatState[,] currState = new SeatState[numRows, numCols];
@ -196,15 +214,13 @@ namespace _2020
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++)
Parallel.For(0, numRows, (i) =>
{
for (int j = 0; j < numCols; j++)
{
@ -212,25 +228,20 @@ namespace _2020
if (currState[i, j] == SeatState.Empty && numOccupied == 0)
{
nextState[i, j] = SeatState.Occupied;
numChanges++;
Interlocked.Increment(ref numChanges);
}
else if (currState[i, j] == SeatState.Occupied && numOccupied >= 4)
{
nextState[i, j] = SeatState.Empty;
numChanges++;
}
if (nextState[i, j] == SeatState.Occupied)
{
totalNumOccupied++;
Interlocked.Increment(ref numChanges);
}
}
}
});
Array.Copy(nextState, currState, numRows * numCols);
}
Debug.WriteLine($"Q11Part1: stabilized after {rounds - 1} rounds, total occupied={totalNumOccupied}");
Debug.WriteLine($"Q11Part1: stabilized after {rounds - 1} rounds, total occupied={GetNumOccupied(currState)}");
}
static void Part2()
@ -240,15 +251,13 @@ namespace _2020
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++)
Parallel.For(0, numRows, (i) =>
{
for (int j = 0; j < numCols; j++)
{
@ -256,25 +265,20 @@ namespace _2020
if (currState[i, j] == SeatState.Empty && numOccupied == 0)
{
nextState[i, j] = SeatState.Occupied;
numChanges++;
Interlocked.Increment(ref numChanges);
}
else if (currState[i, j] == SeatState.Occupied && numOccupied >= 5)
{
nextState[i, j] = SeatState.Empty;
numChanges++;
}
if (nextState[i, j] == SeatState.Occupied)
{
totalNumOccupied++;
Interlocked.Increment(ref numChanges);
}
}
}
});
Array.Copy(nextState, currState, numRows * numCols);
}
Debug.WriteLine($"Q11Part2: stabilized after {rounds - 1} rounds, total occupied={totalNumOccupied}");
Debug.WriteLine($"Q11Part2: stabilized after {rounds - 1} rounds, total occupied={GetNumOccupied(currState)}");
}
}
}