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:

def solution(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 Python

Time spent on task 7 minutes

Notes

not defined yet

Task timeline

Code: 05:35:44 UTC, java, autosave

show code in pop-up

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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: 05:35:44 UTC, java, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11

// 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: 05:35:54 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    pass

Code: 05:37:34 UTC, py, autosave

show code in pop-up

1 2 3 4

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):

Code: 05:38:03 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    perm_set = set()

    for i in A:
        perm_set.add(i)

Code: 05:38:33 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    perm_set = set()
    diff_set = set([i for i in range(1, len(A))])

    for i in A:
        perm_set.add(i)

Code: 05:38:55 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, )])

    for i in A:
        perm_set.add(i)

Code: 05:39:05 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])

    for i in A:
        perm_set.add(i)

Code: 05:39:16 UTC, py, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    print(diff_set)

    for i in A:
        perm_set.add(i)

Analysis

expand all Example tests

▶

example1
the first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, int expected, <class 'NoneType'> found.

stdout:

{1, 2, 3, 4}

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, int expected, <class 'NoneType'> found.

stdout:

{1, 2, 3}

Code: 05:39:31 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    print(diff_set)

    for i in A:
        perm_set.add(i)

Code: 05:39:55 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    print(diff_set)

    for i in A:
        perm_set.add(i)
    
    list(diff_set.difference(perm_set))

Code: 05:40:03 UTC, py, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    print(diff_set)

    for i in A:
        perm_set.add(i)
    
    print(list(diff_set.difference(perm_set)))

Analysis

expand all Example tests

▶

example1
the first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, int expected, <class 'NoneType'> found.

stdout:

{1, 2, 3, 4}
[]

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, int expected, <class 'NoneType'> found.

stdout:

{1, 2, 3}
[2]

Code: 05:40:26 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    print(diff_set)

    for i in A:
        perm_set.add(i)
    
    if list(diff_set.difference(perm_set)) is []""

Code: 05:40:42 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)
    
    if list(diff_set.difference(perm_set)) is []:
        return 1
    else:
        return 0

Code: 05:40:48 UTC, py, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)
    
    if list(diff_set.difference(perm_set)) is []:
        return 1
    else:
        return 0

Analysis

expand all Example tests

▶

example1
the first example test

✘

WRONG ANSWER
got 0 expected 1

0.036 s

WRONG ANSWER, got 0 expected 1

▶

example2
the second example test

✔

0.036 s

Code: 05:41:12 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

Code: 05:41:25 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

    print(list(diff_set.difference(perm_set)))

Code: 05:41:26 UTC, py, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

    print(list(diff_set.difference(perm_set)))

Analysis

expand all Example tests

▶

example1
the first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, int expected, <class 'NoneType'> found.

stdout:

[]

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.036 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, int expected, <class 'NoneType'> found.

stdout:

[2]

Code: 05:41:54 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

    if list(diff_set.difference(perm_set)) == []:
        return

Code: 05:42:05 UTC, py, verify, result: Passed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

    if list(diff_set.difference(perm_set)) == []:
        return 1   
    return 0

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.036 s

▶

example2
the second example test

✔

0.036 s

Code: 05:42:12 UTC, py, verify, result: Passed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

    if list(diff_set.difference(perm_set)) == []:
        return 1   
    return 0

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.036 s

▶

example2
the second example test

✔

0.036 s

Code: 05:42:15 UTC, py, final, score: 100

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    length_A = len(A)
    perm_set = set()
    diff_set = set([i for i in range(1, length_A + 1)])
    #print(diff_set)

    for i in A:
        perm_set.add(i)

    if list(diff_set.difference(perm_set)) == []:
        return 1   
    return 0

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

✔

0.036 s

▶

example2
the second example test

✔

0.036 s

expand all Correctness tests

▶

extreme_min_max
single element with minimal/maximal value

✔

0.036 s

▶

single
single element

✔

0.036 s

▶

double
two elements

✔

0.036 s

▶

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

✔

0.036 s

▶

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

✔

0.036 s

▶

permutations_of_ranges
permutations of sets like [2..100] for which the anwsers should be false

✔

0.036 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

✔

0.156 s

0.152 s

▶

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

✔

0.164 s

0.156 s

▶

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

✔

0.152 s

0.160 s

▶

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

✔

0.036 s

0.144 s

0.036 s

▶

various_permutations
all sequences are permutations

✔

0.036 s

0.048 s

0.152 s

0.156 s