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You can use several words in query to find by all of them at the same time. In addition, if you are lucky search understands word forms and some synonyms. It supports search by title and author. Examples:
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Results
1.
Editorial for Codeforces Round #748 (Div.3) [problem:1593A]
Idea: [user:MikeMirzayanov,2021-10-15]
<spoiler summary="Tutorial">
[tutorial:1593A]
</spoiler>
<spoiler summary="Solution">
~~~~~
#include <bits/stdc++.h>
using namespace std;
int solveSingle(int best, int other1, int other2)
{
return max(0, max(other1, other2) + 1 - best);
}
int main()
{
int t;
cin >> t;
while (t--)
{
int a, b, c;
cin >> a >> b >> c;
cout << solveSingle(a, b, c) << ' ' << solveSingle(b, a, c) << ' ' << solveSingle(c, a, b) << '\n';
}
return 0;
}
~~~~~
</spoiler>
[problem:1593B]
Idea: [user:MikeMirzayanov,2021-10-15]
<spoiler summary="Tutorial">
[tutorial:1593B]
</spoiler>
<spoiler summary="Solution">
~~~~~
#include <bits/stdc++.h>
using namespace std;
const string subseqs[] = { "00", "25", "50", "75" };
const int INF = 100;
int solve(string& s, string& t)
{
int sptr = s.length() - 1;
int ans = 0;
while (sptr >= 0 && s[sptr] != t[1])
{
sptr--;
ans++;...
Tutorial of Codeforces Round 748 (Div. 3)
2.
spoj subseq i m doing<a href="http://www.spoj.pl/problems/SUBSEQ/"> this</a> (spoj SUBSEQ) problem on spoj...my algo is n*logn bt its giving me TLE ...hw this problem is to b solved ..i m using map...<br>here is the code...<br><br>int main()<br>{<br> map<int,int>list;<br> int t;<br> scanf("%d",&t);<br> while(t--)<br> {<br> list.clear();<br> int n;<br> scanf("%d",&n);<br> int tmp;<br> VI a,sum(n+1);<br> a.pb(0);<br> FOR(i,1,n)<br> {<br> scanf("%d",&tmp);<br> a.pb(tmp);<br> &n...
spoj subseq, i m doing this <http://www.spoj.pl/problems/<B>SUBSEQ</B>/> (spoj SUBSEQ)
problem on
3.
Good Observations: I will account for good observations and ideas while solving problems in codeforces/CodeChef/atcoder . The proofs of the below statements will not be mentioned here; It's advised to do such proofs on your own for exercise.
- Lets say I have a set $S$ consisting of integers, denote its $lcm(S) = L$, I add a new element $x$ to this set $S$ ,
Lets deonte the new set as $S'$,where $S' = union(S , x)$ and its $lcm(S') = L'$. Can we deduce a relation between $L$ and $L'$? We can observe $L = L'$ or $L' >= 2*L$.
<hr>
- We want to find two numbers in an array $A[]$ with maximum common prefix bits in binary representation. It's easy to show that those two numbers always occur as adjacent numbers in $sorted(A[])$
<hr>
- The number of distinct gcd prefixed/suffixed at an index in an array will never exceed $log(A_{max})$
<hr>
- Let's say I have a number $X$, And I apply modulo operation as many times as I wish, i.e $X = X \% {m_i}$ for some different values of ${m...
with $Xor(subseq) = x$. It can be shown that $f(x)$ is always a power of 2.
Strong result: f(x) = 0 or, > - Lets take an array $A$ and let $f(x)$ be number of subsequence with $Xor(
subseq) = x$. It can be
4.
Three Blocks Palindrome (easy version).Top down dp gettting TLE I was solving [three block palindrome (easy version)](https://mirror.codeforces.com/problemset/problem/1335/E1).
I attempted a top down solution which gives correct results but it is giving TLE on 2nd test case.
I wonder if it is there any chance to solve it by using this approach or the constraint given are too tight to even try this out...
I looked at somebody else submissions but they use the same approach as the one suggested in the editorial.
Maybe converting [this code](https://mirror.codeforces.com/contest/1335/submission/202931890) to bottom up there is a chance to get accepted? Any help/hints/suggestion is appreaccited.
The idea behind my approach is just recursively going from left to right and considering all the possible cases such that the first element to be filled will be the one labelled with value v1, the second with value v2, the third with value v3.
Having one of those values = 0 means the block considered in this case is empty (ie no value has been chosen at all, ...
such that there is only one element occurring in the whole subseq). Finally in
case at the end the seq, subseq). Finally in case at the end the seq is not a palindrome I prune the
solution returning INT_MIN.
5.
k-th longest union of increasing subsequences, but common to n(>=2) sequences Hi,
I'm looking for a problem of finding the length of the k-th longest common subsequences. Requiring the subsequences being increasing naturally leads to the k-th longest increasing "common" subseq problem, but what if we only require them being "common"? The limiting law of the length of the k-th longest increasing subsequences has been studied a lot (arbitrary distribution, nonasymptotically, the sequences/words are assumed to be generated from a distribution). But for the "common" setting, only k=1 is discussed and I didn't find an analog even limited to uniformly distributed binary words. (Finding the length of the increasing subseq of a binary string looks quite weird, but some people worked on it anyway...)
I asked some math people working in this field, but they never saw papers like this. I am wondering if there is any OJ problem (since research and programming contests sometimes have gaps...) Did anyone see one that requires a "k-th" and "common" subsequence? Thanks!!
the subsequences being increasing naturally leads to the k-th longest
increasing "common"subseq, " subseq problem, but what if we only require them being "common"? The limiting
law of the length of the
6.
Help In DP Problem Can anyone explain me the solution of [XOMMON problem](https://www.codechef.com/problems/XOMMON) from codechef. I looked at many successful submissions, though don't understand why we sort the pair of int, pair and then do dp calculations. Also, I wonder why my approach is incorrect .
My approach:
for every index,store the max length of subseq and corresponding xor val. To find the same for any index(say i), loop through each index less than the current one (say j), and see if the xor of two,is >= the xor stored at the lower index(j). If it is, look if length of subseq formed exceeds the length stored at i, if yes update xor val and len at i, if it is same, see if xor of two numbers is less than that stored at i, if yes again update.
finally the answer should be the max element of the array len.
approach: for every index,store the max length of subseq and corresponding xor
val. To find the same for, My approach: for every index,store the max length of subseq and corresponding
xor val. To find the
7.
k-th largest sum of continuous subseq of an array Hello guys, I'm having trouble with a problem.
Given an array A and a number k, find the k-th largest continuous subsequence!
I can only think of a brute-force solution using prefix sum, which run in `O(n ^ 2)`. In this problem n could be as large as `1e5`.
Can anyone give me a hint?
Thanks in advance!
k-th largest sum of continuous subseq of an array
8.
Please help with this problem, Segtree? Hi... Given an array of int and we have to find for each subarray if we can get some **fixed sum S** using summing some or all elements of this subarr(taking subseq not subarr). Can we do it in less than O(n*n) ? Like using segment tree or some complex data structure (I know segment tree if you can explain any approach using that It would be nice)? Please help. Thanks in advance.
I know that any of or both the children satisfy the condition then we can easily merge both the nodes but how can we merge if both child don't satisfy the above condition.
UPD: [Here](https://mirror.codeforces.com/edu/course/2/lesson/9/3/practice/contest/307094/problem/I) is the problem
** using summing some or all elements of this subarr(taking subseq not subarr).
Can we do it in less
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