Search found 12 matches

by bluebird
Sat Apr 01, 2006 6:59 pm
Forum: Volume 109 (10900-10999)
Topic: 10997 - Medals
Replies: 10
Views: 2709

Yes, but I guess the test data wasn't that comprehensive--even though my solution was wrong, it somehow got AC.

Regardless, I still get this problem. In your earlier posts, you said that if

j > k > l

and n is large enough, then the actual values of j k and l don't matter. Why is that?
by bluebird
Sat Apr 01, 2006 8:50 am
Forum: Volume 109 (10900-10999)
Topic: 10997 - Medals
Replies: 10
Views: 2709

10997 - Medals

Hi, I can't think of the real/intended way to solve this problem. I managed to make an AC solution by trying the vectors (n,1,1) (n,2,1) .... (n,n,1).....(n,n,n) so basically, I try to change each component from 1 to n. This means I try a total of n^3 different vectors. Clearly, this wasn't the inte...
by bluebird
Thu Nov 03, 2005 3:30 am
Forum: Volume 101 (10100-10199)
Topic: 10149 - Yahtzee
Replies: 20
Views: 11725

junbin, I seriously doubt a brute force approach would even bring you within the 10s time limit. I find it hard to believe that memoization would get you top 25.

Perhaps you would care to explain your approach?
by bluebird
Tue Nov 01, 2005 2:04 am
Forum: Volume 100 (10000-10099)
Topic: 10044 - Erdos Numbers
Replies: 102
Views: 39658

Acc

Finally got AC!!!! Kinda surprised no one spotted my error.
by bluebird
Mon Oct 31, 2005 11:51 pm
Forum: Volume 101 (10100-10199)
Topic: 10150 - Doublets
Replies: 46
Views: 16863

I got TLE as well. I had pretty much the same algorithm as yours, but I tried to speed it up by removing the duplicate words in the dictionary, and I used a boolean array instead of an int array to keep track of visited nodes.
by bluebird
Sun Oct 30, 2005 11:07 pm
Forum: Volume 101 (10100-10199)
Topic: 10150 - Doublets
Replies: 46
Views: 16863

10150 (Doublets) TLE

This is supposed to be a simple BFS graph problem but for some reason I keep getting TLE. My program first stores the dictionary into a sorted, unique vector. Then for each pair of words in a test case I just use a simple BFS with the first word as the source vertex. For each word in the chain, I mo...
by bluebird
Thu Oct 27, 2005 4:13 pm
Forum: C++
Topic: Combinations and Permutations
Replies: 3
Views: 2347

I agree. But next_permutation should still be faster than using a recursive algorithm. Is there a faster way to do permutations/combinations?
by bluebird
Thu Oct 27, 2005 4:08 pm
Forum: Volume 8 (800-899)
Topic: 843 - Crypt Kicker
Replies: 51
Views: 25346

For permutation: Dictionary: dog cat web Encrypted String: xyz abc pqr I need to try dog->xyz cat->abc web->pqr dog->xyz web->abc cat->pqr cat->xyz web->abc dog->pqr etc.. (so I need to permutate the dictionary words) For combination: Dictionary: dog cat web boy Encrypted String: xyz abc I need to ...
by bluebird
Thu Oct 27, 2005 2:42 am
Forum: C++
Topic: Combinations and Permutations
Replies: 3
Views: 2347

Combinations and Permutations

I know in STL you can use the next_permutation algorithm to get permutations in linear time, but how do you get QUICK combinations in C++? e.g. how can I find all the different ways to choose 10 things out of 500 things in less than a few seconds, when the order doesn't matter? I ask because I am ha...
by bluebird
Thu Oct 27, 2005 2:33 am
Forum: Volume 100 (10000-10099)
Topic: 10044 - Erdos Numbers
Replies: 102
Views: 39658

10044 Erdos Number WA

For some reason my program keeps getting WA. I've tried the test cases from the previous post, and my I/O does what the previous posts suggested: Upon closer inspection of my name-reading routine, I see that it was slightly more complicated than I described yesterday. Here's a detailed description (...
by bluebird
Thu Oct 27, 2005 2:14 am
Forum: Volume 8 (800-899)
Topic: 843 - Crypt Kicker
Replies: 51
Views: 25346

843 Crypt Kicker OMG

How did anyone solve something like this in less than 3 hours?? After coding and re-coding for some time I finally managed to write a C++ program that accepts the test cases from http://plg.uwaterloo.ca/~acm00/S98-1/ But it takes about 15 MINUTES. My design is backtracking, so my code should be more...
by bluebird
Thu Oct 20, 2005 5:33 am
Forum: C++
Topic: Sorting (Mutil-dimensional arrays)
Replies: 2
Views: 1869

Sorting (Mutil-dimensional arrays)

In the STL, is there a default function that sorts a rectangular 2D array based on a specified column? For instance, if I have: Array-Index studentID grades 0 5 90 1 6 8 How do I get a list of the students based on grades ranking (i.e. Sort the grades column)? This should be a fairly common task. It...

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