public int FixProgram(Instruction[] instructions)
{
ProgramResult result = new ProgramResult();
for (int i = 0; i < instructions.Length; i++)
{
var instruction = instructions[i];
if (instruction.Operation == Operation.nop)
{
instruction.Operation = Operation.jmp;
result = ProcessInstructions(instructions);
instruction.Operation = Operation.nop;
}
else if (instruction.Operation == Operation.jmp)
{
instruction.Operation = Operation.nop;
result = ProcessInstructions(instructions);
instruction.Operation = Operation.jmp;
}
if (result.NormalTermination == true)
{
return(result.Accumulator);
}
foreach (var reset in instructions)
{
reset.Visits = 0;
}
}
throw new ArgumentException("The program couldn't be fixed");
}
public ProgramResult ProcessInstructions(Instruction[] instructions)
{
bool repeat = false;
int index = 0;
ProgramResult result = new ProgramResult {
Accumulator = 0, NormalTermination = false
};
try
{
while (!repeat)
{
var current = instructions[index];
if (current.Visits == 0)
{
switch (current.Operation)
{
case Operation.nop:
index++;
break;
case Operation.acc:
result.Accumulator += current.Argument;
index++;
break;
case Operation.jmp:
index += current.Argument;
break;
}
}
else
{
repeat = true;
}
current.Visits++;
}
}
catch (Exception e)
{
result.NormalTermination = true;
}
return(result);
}