Day2 updated attempt

main
login000 2024-12-03 10:21:34 +10:30
parent 95702c7a3e
commit 0aa8bb80ba
2 changed files with 116 additions and 169 deletions

View File

@ -9,10 +9,108 @@ namespace Advent24
{ {
internal class Day2 internal class Day2
{ {
private static Boolean ReportIsSafe(String[] levelsArray, Int32? levelIndexToSkip = null)
{
Int32 currentLevel;
Int32? previousLevel = null;
Int32? previousPreviousLevel = null;
Int32 differenceInLevels = 0;
Boolean? isIncreasing = null;
Boolean reportIsSafe = true;
Int32 currentLevelIndex = 0;
foreach (var level in levelsArray)
{
Console.WriteLine("{0:s} {1:d}", " level = ", level);
// if there is no elementIndexToSkip, assume sentinel value -1
// so that it never matches the currentElementIndex
if((levelIndexToSkip ?? -1) == currentLevelIndex)
{
// assume current element doesn't exist, so the previous
// element should be the one that was before it
previousLevel = previousPreviousLevel;
Console.WriteLine("{0:s} {1:d}", " currentLevelIndex (skipped) = ", currentLevelIndex);
// if (currentLevelIndex != 0) Console.ReadKey();
// increment the currentElementIndex and short-circuit the loop
currentLevelIndex++;
continue;
}
currentLevel = System.Convert.ToInt32(level);
if (currentLevel > (previousLevel ?? 0))
{
// first time, so can't tell trend
if (!previousLevel.HasValue) isIncreasing = null;
else if ((!isIncreasing) ?? false)
{
// level was decreasing but is now increasing, so report is unsafe
reportIsSafe = false;
break;
}
else isIncreasing = true;
differenceInLevels = currentLevel - (previousLevel ?? 0);
}
else if (currentLevel < (previousLevel ?? 0))
{
// first time, so can't tell trend
if (!previousLevel.HasValue) isIncreasing = null;
else if (isIncreasing ?? false)
{
// level was increasing but is now decreasing, so report is unsafe
reportIsSafe = false;
break;
}
else isIncreasing = false;
differenceInLevels = (previousLevel ?? 0) - currentLevel;
}
else if (previousLevel.HasValue)
{
// both currentLevel and previousLevel are equal, so report is unsafe
reportIsSafe = false;
break;
}
Console.WriteLine("{0:s} {1:d}", " differenceInLevels = ", differenceInLevels);
Console.WriteLine("{0:s} {1:d}", " isIncreasing = ", isIncreasing);
// control reaches this line if currentLevel = previousLevel
// or if it was previously increasing/decreasing and is also
// currently increasing/decreasing
// confirm that it isn't first time, so a difference in levels is conceptually valid
if (previousLevel.HasValue)
{
// difference in levels is outside the safe band, so report is unsafe
if (differenceInLevels < 1 || differenceInLevels > 3)
{
reportIsSafe = false;
break;
}
}
// control reaches this line if report has not been proven unsafe yet
// updating previousLevel and previousPreviousLevel in preparation for the next iteration
previousPreviousLevel = previousLevel;
previousLevel = currentLevel;
// incrementing the current-element-number indicator
currentLevelIndex++;
}
return reportIsSafe;
}
public Day2() public Day2()
{ {
string fileData = System.IO.File.ReadAllText(@"..\..\..\inputd2.txt"); string fileData = System.IO.File.ReadAllText(@"..\..\..\inputd2.txt");
var reportsArray = fileData.Split('\n'); var reportsArray = fileData.Split('\n', StringSplitOptions.RemoveEmptyEntries);
Int32 numberOfSafeReports = 0; Int32 numberOfSafeReports = 0;
@ -25,177 +123,26 @@ namespace Advent24
var levelsArray = report.Split(' '); var levelsArray = report.Split(' ');
Int32 currentLevel = 0; Int32 numberOfLevels = levelsArray.Length;
Int32? previousLevel = null; Boolean reportIsSafe = false;
Int32? previousPreviousLevel = null;
Int32? discardedLevel = null;
Int32 differenceInLevels = 0;
Boolean? isIncreasing = null;
Boolean reportIsSafe = true;
Boolean problemDampenerEnabled = true;
foreach (var level in levelsArray) // iterate through each index to check subreports
// for safety
for (Int32 i = 0; i < numberOfLevels; i++)
{ {
Console.WriteLine("{0:s} {1:d}", " level = ", level); // check if the current subreport is safe
reportIsSafe = ReportIsSafe(levelsArray, i);
currentLevel = System.Convert.ToInt32(level); // if any subreport is safe, the report is safe,
// so we don't need to check any of the other
// subreports and can break
if (reportIsSafe) break;
}
RestartIteration: // check full report for safety if report is still not proven safe
if (!reportIsSafe)
if (currentLevel > (previousLevel ?? 0)) {
{ reportIsSafe = ReportIsSafe(levelsArray);
// first time, so can't tell trend
if (!previousLevel.HasValue) isIncreasing = null;
else if ((!isIncreasing) ?? false)
{
if (problemDampenerEnabled)
{
// store previous level in discardedLevel to instead be
// able to assume the previous level doesn't exist - only
// if this is the second level
discardedLevel = previousLevel;
// assume the current level didn't exist
previousLevel = previousPreviousLevel;
Console.WriteLine("{0:s} {1:d}", " problemDampenerActivated: new previousLevel = ", previousLevel);
Console.ReadLine();
// problemDampener used, so disabled for the rest of the report
problemDampenerEnabled = false;
// previous level had a value and previousPreviousLevel didn't,
// so this is the second level, so we assume the previous level
// doesn't exist and rerun this iteration
if(discardedLevel.HasValue && !previousPreviousLevel.HasValue)
{
}
// continue to the next iteration
continue;
}
else
{
// level was decreasing but is now increasing, so report is unsafe
reportIsSafe = false;
break;
}
}
else isIncreasing = true;
differenceInLevels = currentLevel - (previousLevel ?? 0);
}
else if (currentLevel < (previousLevel ?? 0))
{
// first time, so can't tell trend
if (!previousLevel.HasValue) isIncreasing = null;
else if (isIncreasing ?? false)
{
if (problemDampenerEnabled)
{
// store previous level in discardedLevel to instead be
// able to assume the previous level doesn't exist - only
// if this is the second level
discardedLevel = previousLevel;
// assume the previous level didn't exist
previousLevel = previousPreviousLevel;
Console.WriteLine("{0:s} {1:d}", " problemDampenerActivated: new previousLevel = ", previousLevel);
Console.ReadLine();
// problemDampener used, so disabled for the rest of the report
problemDampenerEnabled = false;
// continue to the next iteration
continue;
}
else
{
// level was increasing but is now decreasing, so report is unsafe
reportIsSafe = false;
break;
}
}
else isIncreasing = false;
differenceInLevels = (previousLevel ?? 0) - currentLevel;
}
else if(previousLevel.HasValue)
{
if (problemDampenerEnabled)
{
// store previous level in discardedLevel to instead be
// able to assume the previous level doesn't exist - only
// if this is the second level
discardedLevel = previousLevel;
// assume previous level didn't exist
previousLevel = previousPreviousLevel;
Console.WriteLine("{0:s} {1:d}", " problemDampenerActivated: new previousLevel = ", previousLevel);
Console.ReadLine();
// problemDampener used, so disabled for the rest of the report
problemDampenerEnabled = false;
// continue to the next iteration
continue;
}
else
{
// both currentLevel and previousLevel are equal, so report is unsafe
reportIsSafe = false;
break;
}
}
Console.WriteLine("{0:s} {1:d}", " differenceInLevels = ", differenceInLevels);
Console.WriteLine("{0:s} {1:d}", " isIncreasing = ", isIncreasing);
// control reaches this line if currentLevel = previousLevel
// or if it was previously increasing/decreasing and is also
// currently increasing/decreasing
// confirm that it isn't first time, so a difference in levels is conceptually valid
if (previousLevel.HasValue)
{
// difference in levels is outside the safe band, so report is unsafe
if (differenceInLevels < 1 || differenceInLevels > 3)
{
if (problemDampenerEnabled)
{
// store previous level in discardedLevel to instead be
// able to assume the previous level doesn't exist - only
// if this is the second level
discardedLevel = previousLevel;
// assume the previous level didn't exist
previousLevel = previousPreviousLevel;
Console.WriteLine("{0:s} {1:d}", " problemDampenerActivated: new previousLevel = ", previousLevel);
Console.ReadLine();
// problemDampener used, so disabled for the rest of the report
problemDampenerEnabled = false;
// continue to the next iteration
continue;
}
else
{
reportIsSafe = false;
break;
}
}
}
// control reaches this line if report has not been proven unsafe yet
// updating previousPreviousLevel in preparation for the next iteration
// if problemDampener is still enabled
if(problemDampenerEnabled) previousPreviousLevel = previousLevel;
// updating previousLevel in preparation for the next iteration
previousLevel = currentLevel;
} }
Console.WriteLine("{0:s} {1:d}", " reportIsSafe = ", reportIsSafe); Console.WriteLine("{0:s} {1:d}", " reportIsSafe = ", reportIsSafe);