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 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Java 21
Time spent on task 2 minutes
Notes
not defined yet
Code: 09:24:31 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
int len=A.length;
int count=0;
int tmp=0;
for(int i=0;i<len;i++){
for(int j=i+1;j<len;j++){
if(A[i]>A[j]){
tmp=A[i];
A[i]=A[j];
A[j]=tmp;
}
}
}
//for(int Av:A) System.out.println(Av);
for(int i=0;i<len-1;i++){
if(A[i]!=A[i+1])count++;
}
if(len==0) count=0;
return count;
}
}
Analysis
expand all
Example tests
1.
1.323 s
WRONG ANSWER,
got 2 expected 3
Code: 09:24:43 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");
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
int len=A.length;
int count=1;
int tmp=0;
for(int i=0;i<len;i++){
for(int j=i+1;j<len;j++){
if(A[i]>A[j]){
tmp=A[i];
A[i]=A[j];
A[j]=tmp;
}
}
}
//for(int Av:A) System.out.println(Av);
for(int i=0;i<len-1;i++){
if(A[i]!=A[i+1])count++;
}
if(len==0) count=0;
return count;
}
}
Analysis
Code: 09:24:52 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");
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
int len=A.length;
int count=1;
int tmp=0;
for(int i=0;i<len;i++){
for(int j=i+1;j<len;j++){
if(A[i]>A[j]){
tmp=A[i];
A[i]=A[j];
A[j]=tmp;
}
}
}
//for(int Av:A) System.out.println(Av);
for(int i=0;i<len-1;i++){
if(A[i]!=A[i+1])count++;
}
if(len==0) count=0;
return count;
}
}
Analysis
User test case 1:
[]
Code: 09:25:33 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");
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
int len=A.length;
int count=1;
int tmp=0;
for(int i=0;i<len;i++){
for(int j=i+1;j<len;j++){
if(A[i]>A[j]){
tmp=A[i];
A[i]=A[j];
A[j]=tmp;
}
}
}
for(int i=0;i<len-1;i++){
if(A[i]!=A[i+1])count++;
}
if(len==0) count=0;
return count;
}
}
Analysis
User test case 1:
[]
Code: 09:25:41 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");
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
int len=A.length;
int count=1;
int tmp=0;
for(int i=0;i<len;i++){
for(int j=i+1;j<len;j++){
if(A[i]>A[j]){
tmp=A[i];
A[i]=A[j];
A[j]=tmp;
}
}
}
for(int i=0;i<len-1;i++){
if(A[i]!=A[i+1])count++;
}
if(len==0) count=0;
return count;
}
}Analysis summary
The following issues have been detected: timeout errors.
Analysis
Detected time complexity:
O(N**2)
expand all
Correctness tests
1.
1.326 s
OK
1.
1.327 s
OK
2.
1.328 s
OK
1.
1.325 s
OK
1.
1.337 s
OK
1.
1.333 s
OK
1.
1.327 s
OK
1.
1.326 s
OK
1.
1.325 s
OK
1.
1.322 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: 2.67 sec., time limit: 2.41 sec.
running time: 2.67 sec., time limit: 2.41 sec.
1.
2.674 s
TIMEOUT ERROR,
running time: 2.67 sec., time limit: 2.41 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: >9.00 sec., time limit: 3.61 sec.
running time: >9.00 sec., time limit: 3.61 sec.
1.
9.000 s
TIMEOUT ERROR,
running time: >9.00 sec., time limit: 3.61 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: >9.00 sec., time limit: 3.59 sec.
running time: >9.00 sec., time limit: 3.59 sec.
1.
9.000 s
TIMEOUT ERROR,
running time: >9.00 sec., time limit: 3.59 sec.