public static void Main(string[] args)
{
// check that arguments have been supplied
if (args.Length != 2) {
Console.WriteLine("missing args");
System.Environment.Exit(1);
}
// attempt to open data file
InFile data = new InFile(args[0]);
if (data.OpenError()) {
Console.WriteLine("cannot open " + args[0]);
System.Environment.Exit(1);
}
// attempt to open results file
OutFile results = new OutFile(args[1]);
if (results.OpenError()) {
Console.WriteLine("cannot open " + args[1]);
System.Environment.Exit(1);
}
// various initializations
int total = 0;
IntSet mySet = new IntSet();
IntSet smallSet = new IntSet(1, 2, 3, 4, 5);
string smallSetStr = smallSet.ToString();
// read and process data file
int item = data.ReadInt();
while (!data.NoMoreData()) {
total = total + item;
if (item > 0) mySet.Incl(item);
item = data.ReadInt();
}
// write various results to output file
results.Write("total = ");
results.WriteLine(total, 5);
results.WriteLine("unique positive numbers " + mySet.ToString());
results.WriteLine("union with " + smallSetStr
+ " = " + mySet.Union(smallSet).ToString());
results.WriteLine("intersection with " + smallSetStr
+ " = " + mySet.Intersection(smallSet).ToString());
results.Close();
}
public static void Main(string [] args)
{
const int Max = 32000;
IntSet uncrossed = new IntSet(); // the sieve
int i, n, k, it, iterations, primes = 0; // counters
IO.Write("How many iterations? ");
iterations = IO.ReadInt();
bool display = iterations == 1;
IO.Write("Supply largest number to be tested ");
n = IO.ReadInt();
if (n > Max) {
IO.Write("n too large, sorry");
System.Environment.Exit(1);
}
IO.WriteLine("Prime numbers between 2 and " + n);
IO.WriteLine("-----------------------------------");
for (it = 1; it <= iterations; it++) {
primes = 0;
for (i = 2; i <= n; i++) // clear sieve
uncrossed.Incl(i);
for (i = 2; i <= n; i++) // the passes over the sieve
if (uncrossed.Contains(i)) {
if (display && primes % 8 == 0) { // ensure line not too long
IO.WriteLine();
}
primes++;
if (display) IO.Write(i, 6);
k = i; // now cross out multiples of i
do {
uncrossed.Excl(k);
k += i;
} while (k <= n);
}
if (display) IO.WriteLine();
}
IO.Write(primes + " primes");
}
private IntSet Expand(IntSet old, int newSize)
{
IntSet expandedSet = old.Copy();
if (newSize > old.bitSet.Length) expandedSet.bitSet.Length = newSize;
return expandedSet;
}
public IntSet SymDiff(IntSet that)
{
// Set symmetric difference
int commonSize = max(this.bitSet.Length, that.bitSet.Length);
IntSet one = Expand(this, commonSize);
IntSet two = Expand(that, commonSize);
return new IntSet(one.bitSet.Xor(two.bitSet));
}
public IntSet Union(IntSet that)
{
// Set union
int commonSize = max(this.bitSet.Length, that.bitSet.Length);
IntSet one = Expand(this, commonSize);
IntSet two = Expand(that, commonSize);
return new IntSet(one.bitSet.Or(two.bitSet));
}
/*
public IntSet Intersection(IntSet that) {
// Set intersection
int commonSize = max(this.bitSet.Length, that.bitSet.Length);
IntSet one = Expand(this, commonSize);
IntSet two = Expand(that, commonSize);
return new IntSet(one.bitSet.And(two.bitSet));
} // IntSet.intersection
*/
public IntSet Intersection(IntSet that)
{
// Set intersection
int minSize = min(this.bitSet.Length, that.bitSet.Length);
IntSet one = new IntSet(minSize);
for (int i = 0; i < minSize; i++) one.bitSet[i] = this.bitSet[i] && that.bitSet[i];
return one;
}
public bool Equals(IntSet that)
{
// Value comparison - sets contain same elements
if (that == null) return false;
int commonSize = max(this.bitSet.Length, that.bitSet.Length);
IntSet one = Expand(this, commonSize);
IntSet two = Expand(that, commonSize);
for (int i = 0; i < commonSize; i++) {
if (one.bitSet[i] != two.bitSet[i]) return false;
}
return true;
}
/*
public IntSet Difference(IntSet that) {
// Set difference
int commonSize = max(this.bitSet.Length, that.bitSet.Length);
IntSet one = Expand(this, commonSize);
IntSet two = Expand(that, commonSize);
for (int i = 0; i < commonSize; i++) one.bitSet[i] = one.bitSet[i] && ! two.bitSet[i];
return one;
} // IntSet.Difference
*/
public IntSet Difference(IntSet that)
{
// Set difference
int minSize = min(this.bitSet.Length, that.bitSet.Length);
IntSet one = this.Copy();
for (int i = 0; i < minSize; i++) one.bitSet[i] = one.bitSet[i] && ! that.bitSet[i];
return one;
}
public bool Contains(IntSet that)
{
// Returns true if that is a subset of this set
return that.IsEmpty() || that.Difference(this).IsEmpty();
}
// Empty set constructor
public IntSet(IntSet old)
{
// Construct set from old
this.bitSet = new BitArray(old.bitSet);
}
