Initial data commit

Task/Population-count/Fortran/population-count.f

@@ -0,0 +1,51 @@
+program population_count
+  implicit none
+
+  integer, parameter :: i64 = selected_int_kind(18)
+  integer(i64) :: x
+  integer :: i, n
+
+  x = 1
+  write(*, "(a8)", advance = "no") "3**i :"
+  do i = 1, 30
+    write(*, "(i3)", advance = "no") popcnt(x)
+    x = x * 3
+  end do
+
+  write(*,*)
+  write(*, "(a8)", advance = "no") "Evil :"
+  n = 0
+  x = 0
+  do while(n < 30)
+    if(mod(popcnt(x), 2) == 0) then
+      n = n + 1
+      write(*, "(i3)", advance = "no") x
+    end if
+    x = x + 1
+  end do
+
+  write(*,*)
+  write(*, "(a8)", advance = "no") "Odious :"
+  n = 0
+  x = 0
+  do while(n < 30)
+    if(mod(popcnt(x), 2) /= 0) then
+      n = n + 1
+      write(*, "(i3)", advance = "no") x
+    end if
+    x = x + 1
+  end do
+
+contains
+
+integer function popcnt(x)
+  integer(i64), intent(in) :: x
+  integer :: i
+
+  popcnt = 0
+  do i = 0, 63
+    if(btest(x, i)) popcnt = popcnt + 1
+  end do
+
+end function
+end program