I saw a problem somewhere and I want to know the most efficient for this problem.
You're given t testcases an array aof n elements and q queries. Each query gives you a range l and r. You want to get a subsegment in [l,r] so that the subsegment is sorted in increasing order.
For example
Input
3
5 2
1 2 3 5 4
1 5
3 5
5 2
1 2 3 4 5
1 5
3 5
6 5
1 4 2 3 9 1
1 3
1 2
1 6
3 6
6 6
Output
4
2
5
3
2
2
3
3
1
I heard that problem can bo solved with segment trees but I don't know how