public static void MutateToFindNormalExitAccumulator(string filename)
{
var program = LoadProgram(filename);
int[] nopIndexes = FindJmpIndexes(program);
int accumulator = 0;
for (var i = 0; i < nopIndexes.Length && accumulator == 0; i++)
{
var nopIndex = nopIndexes[i];
var saved = program[nopIndex];
program[nopIndex] = new SimpleInstruction
{
Operator = SimpleProgram.Nop,
};
try
{
accumulator = program.Run();
}
catch (InfiniteLoopException e)
{
// Not this one
}
program[nopIndex] = saved;
}
Console.WriteLine($"Accumulator value on normal program exit is {accumulator}");
}
private static SimpleProgram LoadProgram(string filename)
{
var lines = Utility.ReadLinesFromFile(filename);
var program = new SimpleProgram();
foreach (var line in lines)
{
var parts = line.Split(" ");
var instruction = new SimpleInstruction
{
Operator = parts[0],
Operand = Convert.ToInt32(parts[1])
};
program.Add(instruction);
}
return(program);
}