public static void MergeRuns(DiskFunctionality df, string in1, string in2, string outTape) //merge 1 series from each input
{
int previous1Record = -1, record1 = df.ReadRecord(in1);
int previous2Record = -1, record2 = df.ReadRecord(in2);
while (true)
{
if (record1 != -1 && record2 != -1)
{
if (Compare(record1, record2))
{
if (Compare(previous1Record, record1))
{
df.SaveRecord(record1, outTape);
previous1Record = record1;
record1 = df.ReadRecord(in1);
}
else
{
df.ReturnRecord(in1);
while (true)
{
if (Compare(previous2Record, record2))
{
df.SaveRecord(record2, outTape);
previous2Record = record2;
record2 = df.ReadRecord(in2);
if (record2 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in2);
return;
}
}
}
}
else
{
if (Compare(previous2Record, record2))
{
df.SaveRecord(record2, outTape);
previous2Record = record2;
record2 = df.ReadRecord(in2);
}
else
{
df.ReturnRecord(in2);
while (true)
{
if (Compare(previous1Record, record1))
{
df.SaveRecord(record1, outTape);
previous1Record = record1;
record1 = df.ReadRecord(in1);
if (record1 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in1);
return;
}
}
}
}
}
else
{
if (record2 == -1)
{
while (true)
{
if (Compare(previous1Record, record1))
{
df.SaveRecord(record1, outTape);
previous1Record = record1;
record1 = df.ReadRecord(in1);
if (record1 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in1);
return;
}
}
}
else if (record1 == -1)
{
while (true)
{
if (Compare(previous2Record, record2))
{
df.SaveRecord(record2, outTape);
previous2Record = record2;
record2 = df.ReadRecord(in2);
if (record2 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in2);
return;
}
}
}
else
{
return;
}
}
}
}
