Tasks Details
easy
1.
Distinct
Compute number of distinct values in an array.
Task Score
75%
Correctness
100%
Performance
0%
Write a function
class Solution { public int solution(int[] A); }
that, given an array A consisting of N integers, returns the number of distinct values in array A.
For example, given array A consisting of six elements such that:
A[0] = 2 A[1] = 1 A[2] = 1 A[3] = 2 A[4] = 3 A[5] = 1the function should return 3, because there are 3 distinct values appearing in array A, namely 1, 2 and 3.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [0..100,000];
- each element of array A is an integer within the range [−1,000,000..1,000,000].
Copyright 2009–2024 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Java 8
Time spent on task 1 minutes
Notes
not defined yet
Task timeline
Code: 07:44:49 UTC,
java,
verify,
result: Failed
// 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(int[] A) {
// write your code in Java SE 8
ArrayList<Integer> array = new ArrayList<>();
int checkInt = 0;
for(int i = 0 ; i < A.length; i++){
checkInt = A[i];
boolean isDistinct = false;
for(int j = 0 ; j < array.size() ; j++){
if(A[i] == array.get(j) ){
isDistinct = true;
}
}
if(!isDistinct){
array.add(checkInt);
}
}
return array.size();
}
}
Analysis
Compile error
Solution.java:10: error: cannot find symbol
ArrayList<Integer> array = new ArrayList<>();
^
symbol: class ArrayList
location: class Solution
Solution.java:10: error: cannot find symbol
ArrayList<Integer> array = new ArrayList<>();
^
symbol: class ArrayList
location: class Solution
2 errors
Code: 07:45:00 UTC,
java,
verify,
result: Passed
// 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");
import java.util.ArrayList;
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
ArrayList<Integer> array = new ArrayList<>();
int checkInt = 0;
for(int i = 0 ; i < A.length; i++){
checkInt = A[i];
boolean isDistinct = false;
for(int j = 0 ; j < array.size() ; j++){
if(A[i] == array.get(j) ){
isDistinct = true;
}
}
if(!isDistinct){
array.add(checkInt);
}
}
return array.size();
}
}
Analysis
Code: 07:45:06 UTC,
java,
verify,
result: Passed
// 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");
import java.util.ArrayList;
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
ArrayList<Integer> array = new ArrayList<>();
int checkInt = 0;
for(int i = 0 ; i < A.length; i++){
checkInt = A[i];
boolean isDistinct = false;
for(int j = 0 ; j < array.size() ; j++){
if(A[i] == array.get(j) ){
isDistinct = true;
}
}
if(!isDistinct){
array.add(checkInt);
}
}
return array.size();
}
}
Analysis
Code: 07:45:11 UTC,
java,
final,
score:
75
// 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");
import java.util.ArrayList;
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
ArrayList<Integer> array = new ArrayList<>();
int checkInt = 0;
for(int i = 0 ; i < A.length; i++){
checkInt = A[i];
boolean isDistinct = false;
for(int j = 0 ; j < array.size() ; j++){
if(A[i] == array.get(j) ){
isDistinct = true;
}
}
if(!isDistinct){
array.add(checkInt);
}
}
return array.size();
}
}Analysis summary
The following issues have been detected: timeout errors.
Analysis
Detected time complexity:
O(N**2)
expand all
Correctness tests
1.
0.004 s
OK
1.
0.004 s
OK
2.
0.008 s
OK
1.
0.004 s
OK
1.
0.004 s
OK
1.
0.004 s
OK
1.
0.004 s
OK
1.
0.004 s
OK
1.
0.008 s
OK
1.
0.004 s
OK
expand all
Performance tests
large1
chaotic sequence of values from [0..100K], length=10K
chaotic sequence of values from [0..100K], length=10K
✘
TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.14 sec.
running time: >6.00 sec., time limit: 0.14 sec.
1.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.14 sec.
large_random1
chaotic sequence of values from [-1M..1M], length=100K
chaotic sequence of values from [-1M..1M], length=100K
✘
TIMEOUT ERROR
running time: >7.00 sec., time limit: 1.30 sec.
running time: >7.00 sec., time limit: 1.30 sec.
1.
7.000 s
TIMEOUT ERROR,
running time: >7.00 sec., time limit: 1.30 sec.
large_random2
another chaotic sequence of values from [-1M..1M], length=100K
another chaotic sequence of values from [-1M..1M], length=100K
✘
TIMEOUT ERROR
running time: >7.00 sec., time limit: 1.30 sec.
running time: >7.00 sec., time limit: 1.30 sec.
1.
7.000 s
TIMEOUT ERROR,
running time: >7.00 sec., time limit: 1.30 sec.