I think the second hidden block will answer your question - let me know if you have doubts after reading that!

Keshav,

What I am worried about is the constriant. If we do Floyd Warshall, it won't work. Djkstra with heap for all sources too s...

Lets see if you can get it with this 4 word hint.

Try to not read this next hint, it gives it all away...

I see. I like the Stack Overflow link Shreeyash provided. I also like this tutorial on Codeforces: Counting problems from A to B.

Here are my thoughts and observations on it:

• You should think of digit DP problems as j...

The best bit manipulation tutorials are Fun with Bits – topcoder and Bit Manipulation - HackerEarth. Although I haven't tried any of these problems myself, HackerRank seems to have a good collection of problems on bit manipulation.

I find bit manipulation to be useful quite rarely. B...

It is dynamic programming on the digits of a number. It involves problems like this one Codeforces problem 489C.

Also, this might be useful : http://stackoverflow.co...

Well, there is an easier approach.

For each point 1 to N, run DFS from another point and check if all points are reachable from that one point. The key is th...

I got the correct answer for all test cases except for 7th. Anyone facing the same issue?

Well Tarjan's is O(m+n) way too much faster , huh I was a bit overcautious then , :P nevermind thanks

For each node of tree, store maximum value among parent nodes. Thus, store max disparity for each node. That's it.

The way you traverse the tree is essentially dfs, ex...

Can you share your DP approach

Oh lol, I did it using DP. I'll try with dfs now.

Silly me, if two nodes belong to different components then also their value will be true in array and we cant add that edge.

Although this works in Prim's.

Why can't we just use a boolean array to keep track of the vertices that are a part of any component. That will be sufficient to check if an edge can be added or not ?

import java.io.*;
import java.util.*;
 
class AgressiveCows{ 
   static class Fast{

Here is my explanation for the solution to this problem.

Ayush Srivastava's answer to What is the correct approach to solve the SPOJ problem 'Aggressive cow'?

Hoping that the solution will be clear.

why did you do lo = mid but in the hi you did mid -1 , i mean you would normally do a lo = mid +1 and with the hi you do hi=mid-1 , my solution also required me to do only lo = mid to work when i add 1 it did not , do you know why ?