Tasks Details
medium
Find the smallest positive integer that does not occur in a given sequence.
Task Score
100%
Correctness
100%
Performance
100%
This is a demo task.
Write a function:
class Solution { public int solution(int[] A); }
that, given an array A of N integers, returns the smallest positive integer (greater than 0) that does not occur in A.
For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5.
Given A = [1, 2, 3], the function should return 4.
Given A = [−1, −3], the function should return 1.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..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 13 minutes
Notes
not defined yet
Task timeline
Code: 12:04:00 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.Arrays;
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
Arrays.sort(A);
int j=1;
for(int i=0; i<A.length; i++) {
if(A[i] <= 0)
continue;
if(A[i] == j)
j++;
else if(A[i] > j)
break;
}
return j;
}
}
Analysis
Code: 12:04:13 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.Arrays;
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
Arrays.sort(A);
int j=1;
for(int i=0; i<A.length; i++) {
if(A[i] <= 0)
continue;
if(A[i] == j)
j++;
else if(A[i] > j)
break;
}
return j;
}
}
Analysis
Code: 12:04:26 UTC,
java,
final,
score: 
100
// 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.Arrays;
class Solution {
public int solution(int[] A) {
// write your code in Java SE 8
Arrays.sort(A);
int j=1;
for(int i=0; i<A.length; i++) {
if(A[i] <= 0)
continue;
if(A[i] == j)
j++;
else if(A[i] > j)
break;
}
return j;
}
}
Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(N)
expand all
Correctness tests
1.
0.034 s
OK
2.
0.106 s
OK
3.
0.034 s
OK
4.
0.140 s
OK
1.
0.033 s
OK
2.
0.033 s
OK
3.
0.053 s
OK
1.
0.033 s
OK
2.
0.057 s
OK
1.
0.085 s
OK
2.
0.033 s
OK
1.
0.035 s
OK
expand all
Performance tests
1.
0.080 s
OK
2.
0.249 s
OK
3.
0.337 s
OK
1.
0.404 s
OK
1.
0.532 s
OK
2.
0.800 s
OK
1.
0.360 s
OK