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program main
implicit none
integer :: i
do i=1,12
print *,i,log2d(i),log2u(i)
end do
contains
integer function log2d (n)
integer, intent(in) :: n
log2d = bit_size(n) - 1 - leadz(n)
end function log2d
integer function log2u (n)
integer, intent(in) :: n
log2u = bit_size(n) - leadz(n-1)
end function log2u
end program main
log2d :: Double -> Integer
log2d = floor . logBase 2
log2u :: Double -> Integer
log2u = ceiling . logBase 2
main :: IO ()
main = print $ [log2d, log2u] <*> [1..12]
function log2d(n: uint32): integer;
var
temp: uint32;
begin
Result := 0;
temp := 1;
while (temp < n) do
begin
Inc(Result);
temp := 1 shl Result;
end;
if (temp > n) then
Dec(Result);
end;
function log2u(n: uint32): integer;
begin
Result := log2d(n);
if (1 shl Result < n) then
Inc(Result);
end;
var
i: integer;
begin
for i := 1 to 16 do
writeln(i,': log2d = ',log2d(i),', log2u = ',log2u(i));
end.
def log2d(n) = n.bit_length - 1
def log2u(n) = 2 ** log2d(n) == n ? log2d(n) : log2d(n) + 1
(1..12).each{|n| puts "#{n} #{log2d(n)} #{log2u(n)}" }
fn log2d(n: f64) -> f64 {
n.log2().floor()
}
fn log2u(n: f64) -> f64 {
n.log2().ceil()
}
fn main() {
for n in 1..=12 {
let f = f64::from(n);
println!("{} {} {}", n, log2d(f), log2u(f));
}
}