THRBL - Catapult that ball

Bob has unusual problem. In Byteland we can find a lot of hills and cities. King of Byteland ordered Bob to deliver magic balls from one city to another. Unfortunately, Bob has to deliver many magic balls, so walking with them would take too much time for him. Bob came up with great idea - catapulting them.

Byteland is divided into intervals. Each interval contains city and hill.

Bob can catapult magic ball accurately from city A to city B, if between them there isn't higher hill than A's hill.


Every test case contains N and M (N<=50000) (M<=50000), number of intervals and number of balls.

In next line there's N numbers H(H<=10^9) separated by one space.

In next M lines numbers A and B (1<=A,B<=N), number of city from which we want to catapult the ball and number of city to which we want to catapult the ball.


Write one number - number of magic balls that Bob can catapult successfully.


7 3
2 3 5 4 2 1 6
3 5
2 5
4 6


Bob can catapult ball number 1 and 3.

hide comments
abuhanif: 2020-01-24 16:42:27

between means after A and before B
(A,B) not [A,B]

Last edit: 2020-01-24 16:49:31
Vinod Kollipara: 2019-07-29 05:45:59

is anybody able to submit sparse table based solution in java

fardin_abir: 2019-05-29 05:14:33

Accepted, but how to solve this with binary concept?

vcode11: 2019-05-25 12:13:13

AC in one go using sparse table

shoumikk: 2019-05-23 10:42:11

sparse table - 0.02sec

taponidhi: 2018-09-20 16:03:47

Complexity can be O(n) for precomputation and O(1) for query.Just use NGE(Next Greater Element)(0.02 sec) concept.Its a wonderful problem to apply all ur range solving concepts.Make multiple submissions using different concepts.It gave me wonderful clarity and complexity difference idea.

Last edit: 2018-09-20 16:04:32
m2do: 2018-04-26 10:52:04

1. Sparse Tree = 0.04 secs...
2. Segment Tree = 0.04 secs...
3. Square Root Decomposition = 0.11 secs...

lincolnbf: 2016-10-11 03:17:03

binari, use segment tree. check online how to implement it.

binari: 2016-07-27 12:13:10

my code gives TLE, how could I optimize it, the code is so simple. Besides, every array element in given interval must be checked, so how could it be optimized?

Last edit: 2016-07-27 12:13:33
try2catch: 2016-04-04 08:52:31

Forget about [A,B) or (A,B) or[A,B], just take care of following points:
1. if(B-A)<2 , then you know what will be the answer.
2. otherwise get answer of your query in range(A+1,B-1) and compare it with Array[A].

Added by:Krzysztof Lewko
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64