Increase the numbers in apl - matrix

I have the following data:
a b c d
5 9 6 0
3 1 3 2
Characters in the first row, numbers in the second row.
How do I get the character corresponding to the highest number in the second row, and how do I increase the corresponding number in the second row? (For example, here, column b has the highest number, 9, so increase that number by 10%.)
I use Dyalog version 17.1.

With:
⎕←data←3 4⍴'a' 'b' 'c' 'd' 5 9 6 0 3 1 3 2
a b c d
5 9 6 0
3 1 3 2
You can extract the second row with:
2⌷data
5 9 6 0
Now grade it descending, that is, find the indices that would sort it from highest to lowest:
⍒2⌷data
2 3 1 4
The first number is the column we're looking for:
⊃⍒2⌷data
2
Now we can use this to extract the character from the first row:
data[⊂1,⊃⍒2⌷data]
b
But we only need the column index, not the actual character. The full index of the number we want to increase is:
2,⊃⍒2⌷data
2 2
Extracting the data to see that we got the right index:
data[⊂2,⊃⍒2⌷data]
9
Now we can either create a new array with the target value increased by 10%:
1.1×#(⊂2,⊃⍒2⌷data)⊢data
a b c d
5 9.9 6 0
3 1 3 2
Or change it in-place:
data[⊂2,⊃⍒2⌷data]×←1.1
data
a b c d
5 9.9 6 0
3 1 3 2
Try it online!

Related

Algorithm to distribute evenly products value into care packages

i'm currently solving a problem that states:
A company filed for bankruptcy and decided to pay the employees with the last remaining valuable items in the company only if it can be distributed evenly among them so that all of them have at least received 1 item and that the difference between the employee carrying the most valuable items and the employee carrying the least valuable items can not exceed a certain value x;
Input:
First row contains number of employee;
Second row contains the x value so that the the difference between the employee carrying the most valuable items and the employee carrying the least valuable items can not exceed;
Third row contains all the items with their value;
Output:
First number is the least valuable basket of items value and the second is the most valuable basket;
Example:
Input:
5
4
2 5 3 11 4 3 1 15 7 8 10
Output:
13 15
Input:
5
4
1 1 1 11 1 3 1 2 7 8
Output:
NO (It's impossible to distribute evenly)
Input:
5
10
1 1 1 1
Output:
NO (It's impossible to distribute evenly)
My solution to resolve this problem taking the first input is to, sort the items in ascending or descending order so from
2 5 3 11 4 3 1 15 7 8 10 --> 1 2 3 3 4 5 7 8 10 11 15
then create an adjacency list or just store it in simple variables where we add the biggest number to the lowest basket while iterating the item values array
Element 0: 15
Element 1: 11 <- 3 (sum 14)
Element 2: 10 <- 3 (sum 13)
Element 3: 8 <- 4 <- 1 (sum 13)
Element 4: 7 <- 5 <- 2 (sum 14)
So that my solution will have O(nlogN + 2n), first part using merge sort and then finding max e min value, what do you guys think about this solution?

Sort string in Java

I need way to sort according to the name .
‏ According to the number of letters of the alphabet, the word starts from A to Z,
‏ it's mean you want to count how many a in the two word and the word who have the largest number of letter a, you want to put this word first (swap)
‏ And if their number of a is equal, you will compare the letter after it means b, and if the number of the word is equal, you will compare C, and this is what ... and he will tell you that this is the case Suppose that there are no students who are inspired by the same number of all letters in the same class
My Code contains a class contain a name type of string and main drive contain a array of objects
As I'm a C++ and Python Developer. I can't help you with the Java Code, but according to your query, I think Count Sort is the most suitable for this kind of problem because while sorting numbers it sorts all of them using their Digits.
Example
Input data: 1, 4, 1, 2, 7, 5, 2
Take a count array to store the count of each unique object.
Index: 0 1 2 3 4 5 6 7 8 9
Count: 0 2 2 0 1 1 0 1 0 0
Modify the count array such that each element at each index
stores the sum of previous counts.
Index: 0 1 2 3 4 5 6 7 8 9
Count: 0 2 4 4 5 6 6 7 7 7
The modified count array indicates the position of each object in
the output sequence.
Rotate the array clockwise for one time.
Index: 0 1 2 3 4 5 6 7 8 9
Count: 0 0 2 4 4 5 6 6 7 7
Output each object from the input sequence followed by
increasing its count by 1.
Process the input data: 1, 4, 1, 2, 7, 5, 2. Position of 1 is 0.
Put data 1 at index 0 in output. Increase count by 1 to place next data 1 at an index 1 greater than this index.
Above Example is Taken from https://www.geeksforgeeks.org/counting-sort/

Maximize the minimum score

Given a grid of dimensions A*B with values between 1-9, find a sequence of B numbers that maximizes the minimum number of values matched when compared with A rows.
Describe the certain steps you would take to maximize the minimum score.
Example:
Grid Dimension
A = 5 , B = 10
Grid Values
9 3 9 2 9 9 4 5 7 6
6 3 4 2 8 5 7 5 9 2
4 9 5 8 3 7 3 2 7 6
7 5 8 9 9 4 7 3 3 7
2 6 8 3 2 4 5 4 2 2
Possible Answer
6 3 8 2 9 4 7 5 7 4
Score Calculation
This answer scores
5 when compared with Row 1
5 when compared with Row 2
1 when compared with Row 3
4 when compared with Row 4
2 when compared with Row 5
And thus the minimal score for this answer is 1.
I would go for a local hill-climbing approach that you can complement with a randomization to avoid local minima. Something like:
1. Generate a random starting solution S
2. Compute its score score(S, row) for each row. We'll call min_score(S) the minimum score among all rows for S.
3. Attempt to improve the solution with:
For each digit i (1..B) in S:
If i belongs to a row such that score(S, row) > (min_score(S) + 1) then:
Change i to be the digit of a row with min_score(S). If there was only one row with min_score(S), then min_score(S) has improved by 1
Update the scores of all the rows.
If min_score(S) hasn't improved for more than N iterations of 3, go back to 1 and start with a new random solution.

Quotient in R to hold position in a matrix

Let's assume these are our numbers and we are looking for mod for them
which we can find them using library(pracma)
> mod(c(1,4,23,13,8,9,11,27,32,2),7)
> [1] 1 4 2 6 1 2 4 6 4 2
I want to get a number to see where each number is coming from when it is a matrix?
1,1,4,2,2,2,2,4,5,1
For example; if this is an m by 7 matrix;
We know that it is on 2nd column but what row? 9 is 2nd row (2,2) but not quotient is 1, then 23 is 4th row (4,2) but quotient is 3. Finally, last element 2 is on (1,2).
I am looking for row position since I can use the mod as a column position.
I came out with this
b=c(1,4,23,13,7,9,11,27,32,2)
floor(b/7+1)
[1] 1 1 4 2 2 2 2 4 5 1

Deleting element and getting it's neighbours

I have got a sequence 1 2 3 4 5 6 ... n. Now, I am given a sequence of n deletions - each deletion is a number which I want to delete. I need to respond to each deletion with two numbers - of a left and right neighbour of deleted number (-1 if any doesn't exists).
E.g. I delete 2 - I respond 1 3, then I delete 3 I respond 1 4 , I delete 6 I respond 5 -1 etc.
I want to do it fast - linear of linear-logarithmic time complexity.
What data structure should I use? I guess the key to the solution is the fact that the sequence is sorted.
A doubly-linked list will do fine.
We will store the links in two arrays, prev and next, to allow O(1) access for deletions.
First, for every element and two sentinels at the ends, link it to the previous and next integers:
init ():
for cur := 0, 1, 2, ..., n, n+1:
prev[cur] := cur-1
next[cur] := cur+1
When you delete an element cur, update the links in O(1) like this:
remove (cur):
print (num (prev[cur]), " ", num (next[cur]), newline)
prev[next[cur]] := prev[cur]
next[prev[cur]] := next[cur]
Here, the num wrapper is inserted to print -1 for the sentinels:
num (cur):
if (cur == 0) or (cur == n+1):
return -1
else:
return cur
Here's how it works:
prev next
n = 6 prev/ print 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
/next ------------------- -------------------
init () -1 0 1 2 3 4 5 6 1 2 3 4 5 6 7 8
remove (2) 1 3 1 3 -1 0 1 3 4 5 6 1 3 4 5 6 7 8
remove (3) 1 4 1 4 -1 0 1 4 5 6 1 4 5 6 7 8
remove (6) 5 7 5 -1 -1 0 1 4 5 1 4 5 7 8
remove (1) 0 4 -1 4 -1 0 4 5 4 5 7 8
remove (5) 4 7 4 -1 -1 0 4 4 7 8
remove (4) 0 7 -1 -1 -1 0 7 8
Above, the portions not used anymore are blanked out for clarity.
The respective elements of the arrays still store the values printed above them, but we no longer access them.
As Jim Mischel rightly noted (thanks!), storing the list in two arrays instead of dynamically allocating the storage is crucial to make this O(1) per deletion.
You can use a binary search tree. Deleting from it is logarithmic. If you want to remove n elements and the number of total elements is m, then the complexity of removing n elements from it will be
nlogm

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