Remain calculator exercises project.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
Complete the exercises about bit operator.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
5-7 done.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
5-8 done.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
5-9 done.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
5-10 done.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
5-13 done.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>
Remove test.c and wc.c from repo.

Signed-off-by: acgtyrant <acgtyrant@gmail.com>