OJ Board

About 5 months ago I quit with this problem because I got lost in my code. I wished to make a fast program, that possibly wouldn't need "offline pre-calculation". I wanted to make a code that searched for solutions the same way my brain did. But at that time my way of solving was unclear. ...

Noim, I was not sure if you had got accepted because of this sentence: first i have determined the lcs string for the input string and the reverse of input string This would give an LCS of abcd from abcdcbad, and the palindrome would start with 8 characters in length (abcddcba) and end up with 10 (d...

Noim, did you get AC ? Here is mine + your inputs: abcd aaaa abc aab abababaabababa pqrsabcdpqrs azbzczdzez aaab acaaaba zzzaaazz pooq aoob dabcdcba z aaaab abbbb ababab aaaaa abbcdba And the output my program (version 5) gives: 3 dcbabcd 0 aaaa 2 cbabc 1 baab 0 abababaabababa 9 srqpdcbasrqrsabcdpqr...

I got all answers, exept AC. My method is simillar to what Noim described, but I do not compare the full string against it's full reverse. Instead, I stop the comparison when the left-to-right sub-string 'hits' the right-to-left sub-string. Example: dabccdba = input dabdccdbad = example of minimum s...

I got correct answers for sample input but got WA after submission of code. To find the dimensions of the stack of blocks, I factored the number of blocks with this goal: F1 * F2 * F3 = Blocks F1 + F2 + F3 -->> the smallest possible I used this procedure to find F1, F2 and F3: Num = Blocks for n = 1...

At least for this program, a pseudocode is very helpfull. I was making a pseudo-code to post here because it's easyer for others to understand. Suddenly I perceived my mistake, by reading what I wrote. I was solving it by DP in this manner: All cells start with length 0. Cells out of area have -1 of...

Alun, you checked for mirroring and palindroming, both things at the same time. I think it's easier if you check independently: [cpp]int Len = strlen(S); bool IsPal = true, IsMir = true; for (int i = 0; i < Len; i++) { char C = S ; char Op = S[Len-1-i]; if (C != Op) IsPal = false; if (C != Rev(Op)) ...

First I thought this could be a complicated problem, but soon I wrote a 20 line code and got accepted at first submission. Many ideas passed through my mind and I would like to share them with you. Let's say we have an algorithim that flips adjacent numbers, but it's not optimal. What makes it non-o...

I found 2 bad tricks: --K comand synthax is not K X1 Y1 X2 Y2 C, but K X1 X2 Y1 Y2 C. Why do you think K X1 Y1 X2 Y2 C would be better? In fact, the sintax is as expected: K X1 Y1 X2 Y2 C I made a mistake with that by myself. Maybe I was stressed. Note that I have edited and removed that issue from...

I have lost some days trying to solve this problem. My code had minor errors, but I got trapped with the problem description, which in my opinion is far away from perfect. Now that I got AC, I decided to share my experience and alert others. The problem description states: A common but insecure meth...

why are you interested in primes only? for even numbers, -> ok, can be done with 4 squares what about 15 for example? it is odd and not prime, why is it easier than 3, 5 or any other prime number? Number 15 is not prime, so to get the minimum number of squares, you must use same solution you would ...

For those who still didn't get AC: This problem is relativelly simple, but took me hours. I found 1 bad trick: --in K command, X2>X1 and Y2>Y1, but this is not always true for V and H commands. I got stack overflow (R.E. SIGSEGV) with my simple resursive function, so I switched for a more complex, m...

horape wrote:How do you handle:
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Yes, you are correct. I'm impressed with the way you identified that error from such a complex description I posted. I will rethink my code. Thanks.

None of those, believe it or not...it's the kind of error that makes you bang your head against the wall....:) Hmm now I understood your code. I had not noticed your check() function was recursive and that it did print values (I'm not used to iostream.h). But I think your code could be much simple ...

Stupid error that I found...duh Can I make sujestions ? -=> You probably have noted that you should repeatedly print and check, not just print all then check all and quit. dep[] array is not beeing never decremented and I think you don't need so many arrays. -=> In c++ we normally count from 0 to N...