Test results - Codility

Tasks Details

easy

1. PermCheck

Check whether array A is a permutation.

Task Score

100%

Correctness

100%

Performance

100%

A non-empty array A consisting of N integers is given.

A permutation is a sequence containing each element from 1 to N once, and only once.

For example, array A such that:

A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2

is a permutation, but array A such that:

A[0] = 4 A[1] = 1 A[2] = 3

is not a permutation, because value 2 is missing.

The goal is to check whether array A is a permutation.

Write a function:

class Solution { public int solution(int[] A); }

that, given an array A, returns 1 if array A is a permutation and 0 if it is not.

For example, given array A such that:

A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2

the function should return 1.

Given array A such that:

A[0] = 4 A[1] = 1 A[2] = 3

the function should return 0.

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..1,000,000,000].

Solution

Programming language used Java 21

Time spent on task 9 minutes

Notes

not defined yet

Code: 14:40:55 UTC, java, autosave

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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(int[] A) {
        // write your code in Java SE 8
    }
}

Code: 14:41:01 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i <= set.size(); i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:41:08 UTC, java, verify, result: Passed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i <= set.size(); i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.008 s

▶

example2
the second example test

✔

0.004 s

expand all User tests

▶

test_data1

✔

0.008 s

OK
function result: 1

User test case 1:

[1, 2]

Code: 14:41:22 UTC, java, verify, result: Passed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i <= set.size(); i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✔

0.004 s

expand all User tests

▶

test_data1

✔

0.008 s

OK
function result: 0

User test case 1:

[1, 3]

Code: 14:41:54 UTC, java, verify, result: Passed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i <= set.size(); i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✔

0.004 s

expand all User tests

▶

test_data1

✔

0.004 s

OK
function result: 1

User test case 1:

[1, 1]

Code: 14:42:54 UTC, java, autosave

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boole
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i <= set.size(); i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:43:08 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new  
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i <= set.size(); i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:43:38 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (boolean b : array) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:43:49 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (boolean b : array) {
            if () {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:45:38 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (boolean b : array) {
            if (b) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:45:41 UTC, java, verify, result: Failed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (boolean b : array) {
            if (b == true) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✘

WRONG ANSWER
got 0 expected 1

0.008 s

WRONG ANSWER, got 0 expected 1

▶

example2
the second example test

✔

0.004 s

expand all User tests

▶

test_data1

✔

0.004 s

OK
function result: 0

User test case 1:

[1, 1]

Code: 14:45:56 UTC, java, verify, result: Failed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (boolean b : array) {
            if (b == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✘

WRONG ANSWER
got 0 expected 1

0.004 s

WRONG ANSWER, got 0 expected 1

▶

example2
the second example test

✔

0.004 s

expand all User tests

▶

test_data1

✔

0.004 s

OK
function result: 0

User test case 1:

[1, 1]

Code: 14:46:12 UTC, java, autosave

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i) {
            if (b == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:46:25 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=array.length; i++) {
            if (b == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:46:36 UTC, java, autosave

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[100001]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (b == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:46:46 UTC, java, verify, result: Failed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[A.length + 1]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (b == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

Compile error

Solution.java:11: error: cannot find symbol
            if (b == false) {
                ^
  symbol:   variable b
  location: class Solution
1 error

Code: 14:46:53 UTC, java, verify, result: Failed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[A.length + 1]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (A[i] == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

Compile error

Solution.java:11: error: incomparable types: int and boolean
            if (A[i] == false) {
                     ^
1 error

Code: 14:47:04 UTC, java, verify, result: Failed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[A.length + 1]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (array[i] == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated unexpectedly

0.008 s

RUNTIME ERROR, tested program terminated unexpectedly

stderr:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
	at Solution.solution(Solution.java:7)
	at Exec.run(exec.java:46)
	at Exec.main(exec.java:31)

expand all User tests

▶

test_data1

✔

0.004 s

OK
function result: 0

User test case 1:

[1, 1]

Code: 14:48:10 UTC, java, verify, result: Failed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        boolean[] array = new boolean[A.length + 1]; 
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (array[i] == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated unexpectedly

0.004 s

RUNTIME ERROR, tested program terminated unexpectedly

stderr:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
	at Solution.solution(Solution.java:7)
	at Exec.run(exec.java:46)
	at Exec.main(exec.java:31)

expand all User tests

▶

test_data1

✔

0.004 s

OK
function result: 0

User test case 1:

[1, 1]

Code: 14:48:39 UTC, java, autosave

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Hset  
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (array[i] == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:49:02 UTC, java, autosave

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            array[a] = true;
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (array[i] == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:49:13 UTC, java, autosave

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (array[i] == false) {
                return 0;
            }
        }
        
        return 1;
    }
}

Code: 14:49:34 UTC, java, verify, result: Passed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✔

0.004 s

expand all User tests

▶

test_data1

✔

0.008 s

OK
function result: 0

User test case 1:

[1, 1]

Code: 14:49:42 UTC, java, verify, result: Passed

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.008 s

▶

example2
the second example test

✔

0.008 s

expand all User tests

▶

test_data1

✔

0.008 s

OK
function result: 0

User test case 1:

[1, 1]

Code: 14:49:47 UTC, java, final, score: 100

show code in pop-up

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import java.util.*;

class Solution {
    public int solution(int[] A) {
        Set<Integer> set = new HashSet<>();
        for (int a : A) {
            set.add(a);
        }
        
        for (int i = 1; i<=A.length; i++) {
            if (!set.contains(i)) {
                return 0;
            }
        }
        
        return 1;
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N) or O(N * log(N))

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✔

0.004 s

expand all Correctness tests

▶

extreme_min_max
single element with minimal/maximal value

✔

0.004 s

▶

single
single element

✔

0.004 s

▶

double
two elements

✔

0.004 s

▶

antiSum1
total sum is correct, but it is not a permutation, N <= 10

✔

0.008 s

0.004 s

▶

small_permutation
permutation + one element occurs twice, N = ~100

✔

0.004 s

expand all Performance tests

▶

medium_permutation
permutation + few elements occur twice, N = ~10,000

✔

0.048 s

▶

antiSum2
total sum is correct, but it is not a permutation, N = ~100,000

✔

0.380 s

▶

large_not_permutation
permutation + one element occurs three times, N = ~100,000

✔

0.496 s

▶

large_range
sequence 1, 2, ..., N, N = ~100,000

✔

0.496 s

0.488 s

▶

extreme_values
all the same values, N = ~100,000

✔

0.008 s

0.220 s

0.004 s

▶

various_permutations
all sequences are permutations

✔

0.004 s

0.048 s

0.500 s