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

Task timeline

Code: 04:27:19 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: 04:27:30 UTC, py, autosave

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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: 04:28:35 UTC, py, autosave

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1 2 3 4

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

def solution(A):

Code: 04:28:52 UTC, py, autosave

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1 2 3 4 5 6 7 8

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

import collections
def solution(A):

    count_num =

Code: 04:29:22 UTC, py, autosave

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1 2 3 4 5 6 7 8 9 10

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

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for iin

Code: 04:29:40 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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    print(count_num)

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

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:

defaultdict(<class 'int'>, {2: 2, 1: 3, 3: 1})

Code: 04:29:51 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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    print(count_num.keys())

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

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:

dict_keys([2, 1, 3])

Code: 04:29:56 UTC, py, autosave

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    print(len(count_num.keys())

Code: 04:29:59 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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    print(len(count_num.keys()))

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

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:

Code: 04:30:10 UTC, py, autosave

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    len(count_num.keys())

Code: 04:30:10 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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    len(count_num.keys())

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

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.

Code: 04:30:26 UTC, py, verify, result: Failed

show code in pop-up

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

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

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    len(list(count_num.keys()))

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

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.

Code: 04:30:38 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

Code: 04:30:49 UTC, py, autosave

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

Code: 04:30:54 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

User test case 1:

[]

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.040 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

Code: 04:31:19 UTC, py, autosave

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

Code: 04:31:24 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

User test case 1:

[]

User test case 2:

[1] * -1000000

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

▶

test_data2

✘

RUNTIME ERROR
invalid input, unexpected character: *

0.001 s

RUNTIME ERROR, invalid input, unexpected character: *

Code: 04:31:36 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

User test case 1:

[]

User test case 2:

([1] * -1000000)

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

▶

test_data2

✘

RUNTIME ERROR
invalid input, unexpected character: *

0.001 s

RUNTIME ERROR, invalid input, unexpected character: *

Code: 04:31:49 UTC, py, autosave

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

Code: 04:31:51 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

User test case 1:

[]

User test case 2:

([1])

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

▶

test_data2

✘

RUNTIME ERROR
invalid input, unexpected '[', expecting integer

0.001 s

RUNTIME ERROR, invalid input, unexpected '[', expecting integer

Code: 04:31:59 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

User test case 1:

[]

User test case 2:

[1]

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

▶

test_data2

✔

0.036 s

OK
function result: 1

Code: 04:32:10 UTC, py, verify, result: Passed

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

User test case 1:

[]

User test case 2:

[1]

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

▶

test_data2

✔

0.036 s

OK
function result: 1

Code: 04:32:13 UTC, py, final, score: 100

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")

import collections
def solution(A):

    count_num = collections.defaultdict(int)

    for i in A:
        count_num[i] += 1

    return len(count_num.keys())

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

✔

0.040 s

expand all Correctness tests

▶

extreme_empty
empty sequence

✔

0.040 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

✔

0.040 s

▶

extreme_big_values
sequence with big values, length=5

✔

0.036 s

▶

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

✔

0.040 s

▶

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

✔

0.036 s

▶

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

✔

0.040 s

expand all Performance tests

▶

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

✔

0.048 s

▶

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

✔

0.168 s

▶

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

✔

0.164 s