Add mul func by another people.

Signed-off-by: oooxff <oooxff@gmail.com>
Add divs func.

Signed-off-by: oooxff <oooxff@gmail.com>
change value to value * value.

Signed-off-by: oooxff <oooxff@gmail.com>
Add mul func to hello.c

Signed-off-by: oooxff <oooxff@gmail.com>
Change 1 to true.

Signed-off-by: oooxff <oooxff@gmail.com>
Add stdbool header.

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