Test results - Codility

Tasks Details

easy

1. Distinct

Compute number of distinct values in an array.

Task Score

100%

Correctness

100%

Performance

100%

Write a function

def solution(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] = 1

the 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].

Solution

Programming language used Python

Time spent on task 5 minutes

Notes

not defined yet

Code: 09:13:22 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: 09:13:28 UTC, py, autosave

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# 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: 09:14:07 UTC, py, autosave

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

def solution(A):
    A.sort()

Code: 09:14:38 UTC, py, autosave

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

def solution(A):
    A.sort()
    i = 0
    cnt
    while i < len(A):
        print(A[i])

Code: 09:14:51 UTC, py, verify, result: Failed

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

def solution(A):
    A.sort()
    i = 0
    cnt = 0
    while i < len(A):
        print(A[i])
        
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

RUNTIME ERROR
tested program terminated with exit code 120

0.272 s

RUNTIME ERROR, tested program terminated with exit code 120

stderr:

Traceback (most recent call last):
  File "exec.py", line 129, in <module>
    main()
  File "exec.py", line 91, in main
    result = solution( A )
  File "/tmp/solution.py", line 9, in solution
    print(A[i])
OSError: [Errno 27] File too large
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='ANSI_X3.4-1968'>
OSError: [Errno 27] File too large

stdout:

Code: 09:15:13 UTC, py, autosave

show code in pop-up

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

def solution(A):
    A.sort()
    i = 0
    cnt = 0
    while i < len(A):
        print(A[i])
        i
    return cnt

Code: 09:15:20 UTC, py, verify, result: Failed

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

def solution(A):
    A.sort()
    i = 0
    cnt = 0
    while i < len(A):
        print(A[i])
        i = i+1
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

WRONG ANSWER
got 0 expected 3

0.036 s

WRONG ANSWER, got 0 expected 3

stdout:

Code: 09:15:42 UTC, py, verify, result: Failed

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

def solution(A):
    #A.sort()
    i = 0
    cnt = 0
    while i < len(A):
        print(A[i])
        i = i+1
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

WRONG ANSWER
got 0 expected 3

0.052 s

WRONG ANSWER, got 0 expected 3

stdout:

Code: 09:16:00 UTC, py, autosave

show code in pop-up

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

def solution(A):
    A.sort()
    i = 0
    cnt = 0
    while i < len(A):
        print(A[i])
        i = i+1
    return cnt

Code: 09:16:21 UTC, py, autosave

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

def solution(A):
    A.sort()
    i = 1
    cnt = 0
    while i < len(A):
        if A[i-1] == A[i]
        i = i+1
    return cnt

Code: 09:16:35 UTC, py, verify, result: Failed

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

def solution(A):
    A.sort()
    i = 1
    cnt = 0
    while i < len(A):
        if A[i-1] != A[i]:
            cnt = cnt+1
        i = i+1
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

WRONG ANSWER
got 2 expected 3

0.036 s

WRONG ANSWER, got 2 expected 3

Code: 09:16:43 UTC, py, verify, result: Passed

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

def solution(A):
    A.sort()
    i = 1
    cnt = 1
    while i < len(A):
        if A[i-1] != A[i]:
            cnt = cnt+1
        i = i+1
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

Code: 09:17:14 UTC, py, autosave

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

def solution(A):
    
    A.sort()
    i = 1
    cnt = 1
    while i < len(A):
        if A[i-1] != A[i]:
            cnt = cnt+1
        i = i+1
    return cnt

Code: 09:17:23 UTC, py, verify, result: Passed

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

def solution(A):
    if len(A) == 0: return 0
    A.sort()
    i = 1
    cnt = 1
    while i < len(A):
        if A[i-1] != A[i]:
            cnt = cnt+1
        i = i+1
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

Code: 09:17:38 UTC, py, verify, result: Passed

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

def solution(A):
    if len(A) == 0: return 0
    A.sort()
    i = 1
    cnt = 1
    while i < len(A):
        if A[i-1] != A[i]:
            cnt = cnt+1
        i = i+1
    return cnt

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

Code: 09:17:40 UTC, py, final, score: 100

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

def solution(A):
    if len(A) == 0: return 0
    A.sort()
    i = 1
    cnt = 1
    while i < len(A):
        if A[i-1] != A[i]:
            cnt = cnt+1
        i = i+1
    return cnt

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

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

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

expand all Correctness tests

▶

extreme_empty
empty sequence

✔

0.036 s

▶

extreme_single
sequence of one element

✔

0.036 s

▶

extreme_two_elems
sequence of three distinct elements

✔

0.036 s

▶

extreme_one_value
sequence of 10 equal elements

✔

0.036 s

▶

extreme_negative
sequence of negative elements, length=5

✔

0.036 s

▶

extreme_big_values
sequence with big values, length=5

✔

0.036 s

▶

medium1
chaotic sequence of value sfrom [0..1K], length=100

✔

0.036 s

▶

medium2
chaotic sequence of value sfrom [0..1K], length=200

✔

0.036 s

▶

medium3
chaotic sequence of values from [0..10], length=200

✔

0.036 s

expand all Performance tests

▶

large1
chaotic sequence of values from [0..100K], length=10K

✔

0.052 s

▶

large_random1
chaotic sequence of values from [-1M..1M], length=100K

✔

0.196 s

▶

large_random2
another chaotic sequence of values from [-1M..1M], length=100K

✔

0.200 s