can anyone suggest approach to solve this problem?
https://mirror.codeforces.com/gym/102157/problem/3

given a string S. you have to find maximum product of length of two non overlapping palindromic sequence.
here, non overlapping means only indexes are non overlap.

for example,

1)
s = “abcab”
ans = 3*2 = 6
two palindromic sequence are “aca” and “bb”

2 )
s = nriatdoiarn
ans = 5*5 = 25
two palindromic sequences are “nitin” and ( “radar” or “raoar”)

3 )
s = “abcdef”
ans = 1*1 = 1

please share your solution.

Easy Version link : https://stackoverflow.com/questions/53663721/find-the-maximum-product-of-two-non-overlapping-palindromic-subsequences

Given an array A[1…N] of positive integers, you have to sort it in ascending order in the following manner : In every operation, select any 2 non-overlapping sub-arrays of equal length and swap them. i.e, select two sub-arrays A[i…(i+k-1)] and A[j…(j+k-1)] such that i+k-1 < j and swap A[i] with A[j], A[i+1] with A[j+1] … and A[i+k-1] with A[j+k-1].

Example:
For n=6
6 7 8 1 2 3
Only one operation is needed as after swapping (6 7 8) and (1 2 3 ) sub arrays
we can get 1 2 3 6 7 8 , that is sorted.

How can we figure out minimum number of swaps in most effective way ? and what is minimum time complexity ?

hackereath link :
https://www.hackerearth.com/challenges/competitive/japan-national-programming-challenge/approximate/swap-and-sort/description/

Problem :

This is the time of Christmas and Santa wants to distribute gifts to M children. He has N number of boxes, and each box contains some chocolates. Now, Santa wants to distribute N boxes to M children keeping in mind that distribution should be as fair as possible. To fairly distribute the gift boxes, Santa wants to minimize the maximum number of choclates gifted to a child.
Formally, given M number of children and N boxes, where each box contains some amount of chocolates. The task is to minimize the maximum number of chocolate gifted to a child.
In another word, you have to divide array into M subset such that maximum sum of subset is minimized.
Input:
First line of input contains number of testcases T. For each testcase, there will be three lines of input. First line contains N number of gift boxes, next line contains choclates in each of the N boxes. Last line contains number of children.
Output:
For each testcase, print the minimum number of maximum chocolate a child get.
Constraints:
1 <= T <= 100
1 <= N, M <= 10^6
1 <= A[i] <= 10^8

Example:
Input:
1
4
12 34 67 200
3

Output:
200

Explanation:
Testcase 1: Minimum 200 chocolates will be given to a child which gets the maximum number of chocolate.
Another Corner Case : n = 5 and M=3
array is : [ 3 4 5 5 8]
answer is : 9

how to solve? i didn’t figure out.

how to solve this problem?

problem link: https://www.hackerearth.com/problem/algorithm/gcd-on-tree-6c5cdfba/description/

how to apply centroid decomposition in this problem? or any other approach to solve this problem?