Tasks Details
medium
Find the minimal nucleotide from a range of sequence DNA.
Task Score
62%
Correctness
100%
Performance
0%
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] = 6The 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] = 6the 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.
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Java 8
Time spent on task 4 minutes
Notes
not defined yet
Code: 02:42:01 UTC,
java,
autosave
Code: 02:42:06 UTC,
java,
autosave
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'G':
return 2;
case 'C':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Code: 02:42:17 UTC,
java,
verify,
result: Passed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'G':
return 2;
case 'C':
return 3;
case 'T':
return 4;
}
return -1;
}
}
User test case 1:
['C', [0], [0]]
Analysis
Code: 02:42:37 UTC,
java,
autosave
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'C':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Code: 02:42:42 UTC,
java,
verify,
result: Failed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
User test case 1:
['C', [0], [0]]
Analysis
expand all
Example tests
1.
0.004 s
WRONG ANSWER,
got [3, 4, 1] expected [2, 4, 1]
Code: 02:42:53 UTC,
java,
verify,
result: Failed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
User test case 1:
['C', [0], [0]]
Analysis
expand all
Example tests
1.
0.004 s
WRONG ANSWER,
got [3, 4, 1] expected [2, 4, 1]
Code: 02:43:51 UTC,
java,
autosave
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
Syst
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Code: 02:43:55 UTC,
java,
verify,
result: Failed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
System.out.println(S.charAt(j));
if (min > j) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
User test case 1:
['C', [0], [0]]
Analysis
expand all
Example tests
1.
0.004 s
WRONG ANSWER,
got [3, 4, 1] expected [2, 4, 1]
stdout:
G C C T C A G C C T A
Code: 02:44:32 UTC,
java,
autosave
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
System.out.println(S.charAt(j));
if (min > getInpactorFactor(S.charAt(j))) {
min = getInpactorFactor(S.charAt(j));
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Code: 02:44:46 UTC,
java,
autosave
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
int minFactor = getInpactorFactor(S.charAt(j));
if (min > getInpactorFactor(S.charAt(j))) {
min = minFactor;
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Code: 02:44:58 UTC,
java,
autosave
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int min = 4;
for (int j = P[i]; j <= Q[i]; j++) {
int minFactor = getInpactorFactor(S.charAt(j));
if (min > getImpactorFactor(S.charAt(j))) {
min = minFactr;
}
}
answer[i] = min;
}
return answer;
}
private int getInpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Code: 02:45:19 UTC,
java,
verify,
result: Failed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int minFactor = 4;
for (int j = P[i]; j <= Q[i]; j++) {
int factor = getInpactorFactor(S.charAt(j));
if (minFactor > factor) {
minFactor = factor;
}
}
answer[i] = minFactor;
}
return answer;
}
private int getImpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
Analysis
Compile error
Solution.java:10: error: cannot find symbol
int factor = getInpactorFactor(S.charAt(j));
^
symbol: method getInpactorFactor(char)
location: class Solution
1 error
Code: 02:45:27 UTC,
java,
verify,
result: Passed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int minFactor = 4;
for (int j = P[i]; j <= Q[i]; j++) {
int factor = getImpactorFactor(S.charAt(j));
if (minFactor > factor) {
minFactor = factor;
}
}
answer[i] = minFactor;
}
return answer;
}
private int getImpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
User test case 1:
['C', [0], [0]]
Analysis
Code: 02:45:37 UTC,
java,
verify,
result: Passed
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int minFactor = 4;
for (int j = P[i]; j <= Q[i]; j++) {
int factor = getImpactorFactor(S.charAt(j));
if (minFactor > factor) {
minFactor = factor;
}
}
answer[i] = minFactor;
}
return answer;
}
private int getImpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}
User test case 1:
['C', [0], [0]]
Analysis
Code: 02:45:42 UTC,
java,
final,
score:
62
import java.util.*;
class Solution {
public int[] solution(String S, int[] P, int[] Q) {
int[] answer = new int[P.length];
for (int i = 0; i < P.length; i++) {
int minFactor = 4;
for (int j = P[i]; j <= Q[i]; j++) {
int factor = getImpactorFactor(S.charAt(j));
if (minFactor > factor) {
minFactor = factor;
}
}
answer[i] = minFactor;
}
return answer;
}
private int getImpactorFactor(char c) {
switch (c) {
case 'A':
return 1;
case 'C':
return 2;
case 'G':
return 3;
case 'T':
return 4;
}
return -1;
}
}Analysis summary
The following issues have been detected: timeout errors.
Analysis
Detected time complexity:
O(N * M)
expand all
Correctness tests
1.
0.004 s
OK
2.
0.004 s
OK
3.
0.004 s
OK
4.
0.004 s
OK
1.
0.004 s
OK
2.
0.004 s
OK
3.
0.004 s
OK
4.
0.008 s
OK
1.
0.004 s
OK
2.
0.004 s
OK
3.
0.004 s
OK
1.
0.004 s
OK
1.
0.008 s
OK
expand all
Performance tests
almost_all_same_letters
GGGGGG..??..GGGGGG..??..GGGGGG
GGGGGG..??..GGGGGG..??..GGGGGG
✘
TIMEOUT ERROR
running time: >8.00 sec., time limit: 2.77 sec.
running time: >8.00 sec., time limit: 2.77 sec.
1.
8.000 s
TIMEOUT ERROR,
running time: >8.00 sec., time limit: 2.77 sec.
2.
0.072 s
OK
large_random
large random string, length
large random string, length
✘
TIMEOUT ERROR
running time: >8.00 sec., time limit: 2.69 sec.
running time: >8.00 sec., time limit: 2.69 sec.
1.
8.000 s
TIMEOUT ERROR,
running time: >8.00 sec., time limit: 2.69 sec.
1.
9.000 s
TIMEOUT ERROR,
running time: >9.00 sec., time limit: 3.17 sec.