func toBitSet(number uint64) bitset.BitSet {
lsbString := strconv.FormatUint(number, 2)
var b bitset.BitSet
for i, character := range lsbString {
if character == '1' {
b.Set(uint(len(lsbString)-1) - uint(i))
}
}
return b
}
func solve(pr *codejam.Problem, d *data) {
n := len(d.pairs)
ais := make([]int, n)
bis := make([]int, n)
for i := 0; i < n; i++ {
ais[i] = i
bis[i] = i
}
psa := &pairSorter{
indices: ais,
pairs: d.pairs,
column: 0,
}
psb := &pairSorter{
indices: bis,
pairs: d.pairs,
column: 1,
}
sort.Sort(psa)
sort.Sort(psb)
var nw int
for i := 0; i < n-1; i++ {
v := d.pairs[ais[i]][1]
k := sort.Search(n, func(j int) bool {
return d.pairs[bis[j]][1] >= v
})
// count common indices from ais[i+1:] and bis[:k]
var ba bitset.BitSet
var bb bitset.BitSet
for _, c := range ais[i+1:] {
ba.Set(uint(c))
}
for _, c := range bis[:k] {
bb.Set(uint(c))
}
nw += int(ba.IntersectionCardinality(&bb))
}
pr.Write(fmt.Sprintf("Case #%d: %d\n", d.testIndex, nw))
}