Question

think doing还是think to do 还是都可以？

Answer 1

think后面一般接that从句不过think后面也可以接不定式，即think
to
do
sth.
你说的think
doing是that从句省略中that
的情况，这里的doing是动名词，不是动词

Answer 2

think后面一般接that从句
不过think后面也可以接不定式，即think
to
do
sth.
例：
i
never
thought
to
see
you
here!
我真想不到会在这儿见到你！