OJ Board

experts, any hints how to solve this problem in O(n2) ???

Can somebody Tell why the result for first Case is that ...

we can make 7 by this these ways
-1+2-3+4+5 =7
+1+2+3-4+5 =7
+1-2-3-4-5 =7

Could someone explain the output ...

count the number of all devisors of all numbers of each row ...
now if he Xor of these numbers is zero print no else yes ...
see the problem in my previous comment ..

there is a Nice solution to this problem ...
solve 10290 an easier version of this problem ..

Solved it By Dijkstra ...

search it on .. http://www.google.com/

Just try to Remove all possible Edges ... and check if the Graph is DAG ... and if there is a path that Goes trough all vertexes or not

i didnt use many optimization ... only used Memorization (Using STL map )... also Calculated the result for i:0...10^6 using incremental method ... it tool 4s To calculate FOR 10^6 but FOR this Test Case 2 750 749 999999999999999 it took minutes to complete ... so i didnt try much other minor optimi...

i implemented this approach, but i time out (
could someone help us on this ?
thanks in advance

I used multi source bidirectional BFS as it would be very very much faster....

Is There Any Possible Ideas on this Problem ...
FOR solving O(N*K)???

// This DFS calculate maximum cycle length.

From this line in your code i think your algorithm is wrong
you should not find a Cycle ... you should Remove the Extra Edge and then Find the Lenght of the DAG ..

Find the number of each Prime in C ... and then check A%(Pi^ci) ...
think what can you get from the result of A%(Pi^ci) ...

no, you need only primes up to SQRT(10^7)...
each number has at most only one prime number Greater than sqrt(n);

Leonid , would you please send me your code ?
i dont really understand what the problem is

angeh.a2@gmail.com

(if you send your solution for 11828 - Palindrome Again i'll be Really Grateful , i'm still stock on that problem ( )

Thanks ...