import java.util.BitSet;
public class BitsetTest {
public static void main(String[] args) {
BitSet bits = new BitSet(16);
bits.set(5);
bits.set(1);
BitSet other = new BitSet(16);
other.set(5);
assertTrue("bit 1 is set", bits.get(1));
assertTrue("bit 5 is set", bits.get(5));
assertTrue("bit 0 is not set", !bits.get(0));
assertTrue("bit 16 is not set", !bits.get(16));
assertCardinality(bits, 2);
bits.and(other);
assertTrue("bit 5 is set", bits.get(5));
assertTrue("bit 1 is not set", !bits.get(1));
assertCardinality(bits, 1);
bits.set(100);
assertTrue("bit 100 is set", bits.get(100));
assertTrue("bit 101 is not set", !bits.get(101));
assertCardinality(bits, 2);
other.set(101);
bits.or(other);
assertTrue("bit 101 is set", bits.get(101));
assertEquals("first bit is 5", 5, bits.nextSetBit(0));
assertEquals("first bit is 5 from 3", 5, bits.nextSetBit(4));
assertEquals("first bit is 5 from 5", 5, bits.nextSetBit(5));
assertEquals("second bit is 100", 100, bits.nextSetBit(6));
assertEquals("second bit is 100 from 100", 100, bits.nextSetBit(100));
assertEquals("third bit is 101", 101, bits.nextSetBit(101));
assertEquals("there is no 4th bit", -1, bits.nextSetBit(102));
assertCardinality(bits, 3);
assertEquals("first empty bit is 0", 0, bits.nextClearBit(0));
assertEquals("after 5, 6 is empty", 6, bits.nextClearBit(5));
assertEquals("after 100, 102 is empty", 102, bits.nextClearBit(100));
testFlip();
testClear();
BitSet expandingSet = new BitSet();
//should force us to have 3 partitions.
expandingSet.set(128);
}
private static void testFlip() {
/* simple case */
BitSet bitset = new BitSet();
bitset.set(0);
bitset.flip(0, 0);
assertTrue("Should not be flipped with 0 length range", bitset.get(0));
bitset.flip(0, 1);
assertTrue("Should be false with range of one", !bitset.get(0));
bitset.flip(0);
assertTrue("Should be true again", bitset.get(0));
/* need to grow */
bitset.flip(1000);
assertTrue("1000 should be true", bitset.get(1000));
assertTrue("1001 should be false", !bitset.get(1001));
assertTrue("999 should be false", !bitset.get(999));
/* Range over 2 segments */
bitset.flip(60, 70);
assertTrue("59 should be false", !bitset.get(59));
for (int i=60; i < 70; ++i) {
assertTrue(i + " should be true", bitset.get(i));
}
assertTrue("70 should be false", !bitset.get(70));
}
private static void testClear() {
BitSet bitset = new BitSet();
bitset.set(0, 20);
assertCardinality(bitset, 20);
bitset.clear(1);
assertTrue("bit 1 should be 0", !bitset.get(1));
assertCardinality(bitset, 19);
bitset.clear(0, 3);
assertTrue("bit 0 should be 0", !bitset.get(0));
assertTrue("bit 1 should be 0", !bitset.get(1));
assertTrue("bit 2 should be 0", !bitset.get(2));
assertTrue("bit 3 should be 1", bitset.get(3));
assertCardinality(bitset, 17);
bitset = new BitSet(70);
bitset.flip(0, 65);
for (int i=0; i < 65; ++i) {
assertTrue("bit " + i + " should be set", bitset.get(i));
}
assertTrue("bit 65 should not be set", !bitset.get(65));
}
static void assertTrue(String msg, boolean flag) {
if (flag) {
System.out.println(msg + " : OK.");
} else {
throw new RuntimeException("Error:"+msg);
}
}
static void assertEquals(String msg, int expected, int actual) {
if (expected==actual) {
System.out.println(msg + " : OK. ["+actual+']');
} else {
throw new RuntimeException("Error:"+msg+" expected:"+expected+", actual:"+actual);
}
}
static void assertCardinality(BitSet set, int expectedCardinality) {
assertEquals("Checking cardinality", expectedCardinality, set.cardinality());
}
}