# Help for special permutation

https://www.codechef.com/CLWC2021/problems/CLWI21F
i am trying this problem since contest ended and not getting could you guys can explain so that
we beginner can also understand

bro you need to know what is a subarray and what is a permutation ? .
subarray :- It is continous part of array . you can read more about it here :- Subarray/Substring vs Subsequence and Programs to Generate them - GeeksforGeeks

permutation :- An array of size is a permutation of n when it contains element from 1 to n

I can explain you we need to check for permutations for 1<= i <= n
then we need to check for each i there is a subarray which is a permutation too .
let us see test case 1:-

``````8
2 1 3 5 4 6 8 7
``````

for i = 1 there is a subarray which is permuation of 1 —>`[ 1 ]`
for i=2 there is a subarray which is permuation of 2 ---->` [2,1]`
for i=3 there is a subarray which is permuation of 3 ---->` [ 2 ,1 ,3]`
for i=4 there is no subarraywhich is permuation of 4
similar is case when i=5.
but for i=6 we have a subarray which is permuation of 6 —> `[ 2 , 1, 3, 5,4 ,6] `

• for which we have a subarray we add 1 in string else we add 0

thanks
i understand the problem but not getting idea to solve this i was asking for that

I thought you didn’t got question my bad .