Test results - Codility

Tasks Details

medium

1. GenomicRangeQuery

Find the minimal nucleotide from a range of sequence DNA.

100%

A DNA sequence can be represented as a string consisting of the letters A, C, G and T, which correspond to the types of successive nucleotides in the sequence. Each nucleotide has an impact factor, which is an integer. Nucleotides of types A, C, G and T have impact factors of 1, 2, 3 and 4, respectively. You are going to answer several queries of the form: What is the minimal impact factor of nucleotides contained in a particular part of the given DNA sequence?

The DNA sequence is given as a non-empty string S = S[0]S[1]...S[N-1] consisting of N characters. There are M queries, which are given in non-empty arrays P and Q, each consisting of M integers. The K-th query (0 ≤ K < M) requires you to find the minimal impact factor of nucleotides contained in the DNA sequence between positions P[K] and Q[K] (inclusive).

For example, consider string S = CAGCCTA and arrays P, Q such that:

P[0] = 2 Q[0] = 4 P[1] = 5 Q[1] = 5 P[2] = 0 Q[2] = 6

The answers to these M = 3 queries are as follows:

The part of the DNA between positions 2 and 4 contains nucleotides G and C (twice), whose impact factors are 3 and 2 respectively, so the answer is 2.

The part between positions 5 and 5 contains a single nucleotide T, whose impact factor is 4, so the answer is 4.

The part between positions 0 and 6 (the whole string) contains all nucleotides, in particular nucleotide A whose impact factor is 1, so the answer is 1.

Write a function:

object Solution { def solution(s: String, p: Array[Int], q: Array[Int]): Array[Int] }

that, given a non-empty string S consisting of N characters and two non-empty arrays P and Q consisting of M integers, returns an array consisting of M integers specifying the consecutive answers to all queries.

Result array should be returned as an array of integers.

For example, given the string S = CAGCCTA and arrays P, Q such that:

P[0] = 2 Q[0] = 4 P[1] = 5 Q[1] = 5 P[2] = 0 Q[2] = 6

the function should return the values [2, 4, 1], as explained above.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [1..100,000];

M is an integer within the range [1..50,000];

each element of arrays P and Q is an integer within the range [0..N - 1];

P[K] ≤ Q[K], where 0 ≤ K < M;

string S consists only of upper-case English letters A, C, G, T.

Solution

Programming language used Scala

Time spent on task 19 minutes

Notes

not defined yet

Task timeline

Code: 13:10:32 UTC, scala, verify, result: Passed

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

import scala.collection.JavaConversions._

// you can write to stdout for debugging purposes, e.g.
// println("this is a debug message")

object Solution {
    def solution(S: String, P: Array[Int], Q: Array[Int]): Array[Int] = {
        
        
        val resp = for(ind <- 0 to P.length-1) yield {

  val sub= S.substring(P(ind),Q(ind)+1)

  println(sub)

  var factor = 4

  if(sub.contains("A")) {factor=1}
  else{
    if(sub.contains("C")) {factor=2}
    else{
      if(sub.contains("G")) {factor=3}
    }
  }
 factor

}
        
        return resp.toArray
        
    }
}

Analysis

▶

example
example test

✔

Code: 13:11:10 UTC, scala, verify, result: Passed

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

import scala.collection.JavaConversions._

// you can write to stdout for debugging purposes, e.g.
// println("this is a debug message")

object Solution {
    def solution(S: String, P: Array[Int], Q: Array[Int]): Array[Int] = {
        
        
        val resp = for(ind <- 0 to P.length-1) yield {

  val sub= S.substring(P(ind),Q(ind)+1)

  //println(sub)

  var factor = 4

  if(sub.contains("A")) {factor=1}
  else{
    if(sub.contains("C")) {factor=2}
    else{
      if(sub.contains("G")) {factor=3}
    }
  }
 factor

}
        
        return resp.toArray
        
    }
}

Analysis

▶

example
example test

✔

Code: 13:11:23 UTC, scala, verify, result: Passed

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

import scala.collection.JavaConversions._

// you can write to stdout for debugging purposes, e.g.
// println("this is a debug message")

object Solution {
    def solution(S: String, P: Array[Int], Q: Array[Int]): Array[Int] = {
        
        
        val resp = for(ind <- 0 to P.length-1) yield {

  val sub= S.substring(P(ind),Q(ind)+1)

  //println(sub)

  var factor = 4

  if(sub.contains("A")) {factor=1}
  else{
    if(sub.contains("C")) {factor=2}
    else{
      if(sub.contains("G")) {factor=3}
    }
  }
 factor

}
        
        return resp.toArray
        
    }
}

Analysis

▶

example
example test

✔

Code: 13:11:35 UTC, scala, final, score: 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

import scala.collection.JavaConversions._

// you can write to stdout for debugging purposes, e.g.
// println("this is a debug message")

object Solution {
    def solution(S: String, P: Array[Int], Q: Array[Int]): Array[Int] = {
        
        
        val resp = for(ind <- 0 to P.length-1) yield {

  val sub= S.substring(P(ind),Q(ind)+1)

  //println(sub)

  var factor = 4

  if(sub.contains("A")) {factor=1}
  else{
    if(sub.contains("C")) {factor=2}
    else{
      if(sub.contains("G")) {factor=3}
    }
  }
 factor

}
        
        return resp.toArray
        
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N + M)

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example
example test

✔

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extreme_sinlge
single character string

✔

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extreme_double
double character string

✔

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simple
simple tests

✔

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small_length_string
small length simple string

✔

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small_random
small random string, length = ~300

✔

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almost_all_same_letters
GGGGGG..??..GGGGGG..??..GGGGGG

✔

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large_random
large random string, length

✔

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extreme_large
all max ranges

✔