FAST input and ouput

is it sufficient to write
in the starting or we have to replace every cin or cout to scanf and printf
to avoid TLE
if yes then please write whether “%d” range is upto 1 lakh or not

According to my knowledge, fast io, with cin/cout runs significantly fast. On bigger inputs, scanf/printf run a bit faster than fast io + cin and cout, but I have not yet faced a TLE based on this problem, so I can’t say much.

The range of %d is till the input range
(i.e -10^9 to 10^9).