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:

class Solution { public int[] solution(String S, int[] P, int[] Q); }

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 Java 8

Time spent on task 3 minutes

Notes

not defined yet

Task timeline

Code: 14:09:48 UTC, java, verify, result: Passed

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// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[4][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g, t;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            t = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    t = 1;
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
            prefixSums[3][i + 1] = prefixSums[3][i] + t;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Analysis

▶

example
example test

✔

Code: 14:10:20 UTC, java, autosave

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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[３][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g, t;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            t = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    t = 1;
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
            prefixSums[3][i + 1] = prefixSums[3][i] + t;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Code: 14:10:33 UTC, java, autosave

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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[3]][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    t = 1;
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
            prefixSums[3][i + 1] = prefixSums[3][i] + t;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Code: 14:10:44 UTC, java, autosave

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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[3]][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
            prefixSums[3][i + 1] = prefixSums[3][i] + t;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Code: 14:10:54 UTC, java, verify, result: Failed

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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[3]][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Analysis

Compile error

Solution.java:10: error: ';' expected
        int[][] prefixSums = new int[3]][S.length() + 1];
                                       ^
Solution.java:10: error: not a statement
        int[][] prefixSums = new int[3]][S.length() + 1];
                                                    ^
Solution.java:10: error: ';' expected
        int[][] prefixSums = new int[3]][S.length() + 1];
                                                       ^
3 errors

Code: 14:11:07 UTC, java, 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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[3][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Analysis

▶

example
example test

✔

Code: 14:11:31 UTC, java, 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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[3][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Analysis

▶

example
example test

✔

Code: 14:11:36 UTC, java, 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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

// you can also use imports, for example:
// import java.util.*;

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

class Solution {
    public int[] solution(String S, int[] P, int[] Q) {
int[] goal = new int[P.length];
        int[][] prefixSums = new int[3][S.length() + 1];
        int[] DNA = new int[]{1, 2, 3, 4};
        short a, c, g;
        for (int i = 0; i < S.length(); i++) {
            a = 0;
            c = 0;
            g = 0;
            switch (S.charAt(i)) {
                case 'A':
                    a = 1;
                    break;
                case 'C':
                    c = 1;
                    break;
                case 'G':
                    g = 1;
                    break;
                default:
                    break;
            }
            prefixSums[0][i + 1] = prefixSums[0][i] + a;
            prefixSums[1][i + 1] = prefixSums[1][i] + c;
            prefixSums[2][i + 1] = prefixSums[2][i] + g;
        }

        for (int j = 0; j < P.length; j++) {
            int from = P[j];
            int to = Q[j] + 1;
            if (prefixSums[0][to] - prefixSums[0][from] > 0) {
                goal[j] = DNA[0];
            } else if (prefixSums[1][to] - prefixSums[1][from] > 0) {
                goal[j] = DNA[1];
            } else if (prefixSums[2][to] - prefixSums[2][from] > 0) {
                goal[j] = DNA[2];
            } else {
                goal[j] = DNA[3];
            }
        }

        return goal;
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N + M)

▶

example
example test

✔

▶

extreme_sinlge
single character string

✔

▶

extreme_double
double character string

✔

▶

simple
simple tests

✔

▶

small_length_string
small length simple string

✔

▶

small_random
small random string, length = ~300

✔

▶

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

✔

▶

large_random
large random string, length

✔

▶

extreme_large
all max ranges

✔