Getting wrong answer in last test case. is the question incomplete

#1

IT gives me wrong ans even if i use next_permutation function of the algorithm library.
ques link: https://hack.codingblocks.com/contests/c/547/361
sol link:
https://ide.geeksforgeeks.org/tIyHKmMxco

#2

check this https://ide.codingblocks.com/s/45044

#3

Ty but, the next_permutaion_function was failing why?