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

int solution(vector<int> &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 C++

Time spent on task 3 minutes

Notes

not defined yet

Task timeline

Code: 15:00:42 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: 15:00:44 UTC, cpp, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9

// you can use includes, for example:
// #include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
}

Code: 15:00:49 UTC, cpp, 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 22 23 24 25 26 27 28 29 30 31 32 33 34 35

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001];
    int arr_minus[1000001];
    
    for(int i = 0; i < 1000000; i++){
        arr_plus[i] = i;
        arr_minus[i + 1] = -1 * (i + 1);
    }
    arr_plus[1000000] = 1000000;
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] != 2222222){
                count++;
                arr_plus[num] = 2222222;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:01:16 UTC, cpp, 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 22 23 24 25 26 27 28 29 30 31

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001];
    int arr_minus[1000001];
    

    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] != 2222222){
                count++;
                arr_plus[num] = 2222222;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:01:20 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: 15:01:23 UTC, cpp, 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 22 23 24 25 26 27 28 29 30 31

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001];
    int arr_minus[1000001];
    

    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] != 2222222){
                count++;
                arr_plus[num] = 2222222;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:01:27 UTC, cpp, 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 22 23 24 25 26 27 28 29 30 31 32 33 34 35

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001];
    int arr_minus[1000001];
    
    for(int i = 0; i < 1000000; i++){
        arr_plus[i] = i;
        arr_minus[i + 1] = -1 * (i + 1);
    }
    arr_plus[1000000] = 1000000;
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] != 2222222){
                count++;
                arr_plus[num] = 2222222;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:01:51 UTC, cpp, 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 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] != 2222222){
                count++;
                arr_plus[num] = 2222222;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:02:12 UTC, cpp, 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 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = 2222222;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:02:22 UTC, cpp, 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 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = num;
            }
        }else{
            if(arr_minus[num * -1] != 2222222){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:02:33 UTC, cpp, 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 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = num;
            }
        }else{
            if(arr_minus[num * -1] == '\0'){
                count++;
                arr_minus[num * -1] = 2222222;
            }
        }
    });
    
    return count;
}

Code: 15:02:43 UTC, cpp, 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 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = num;
            }
        }else{
            if(arr_minus[num * -1] == '\0'){
                count++;
                arr_minus[num * -1] = num;
            }
        }
    });
    
    return count;
}

Code: 15:03:06 UTC, cpp, 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 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = 1;
            }
        }else{
            if(arr_minus[num * -1] == '\0'){
                count++;
                arr_minus[num * -1] = 1;
            }
        }
    });
    
    return count;
}

Code: 15:03:16 UTC, cpp, verify, result: Passed

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = 1;
            }
        }else{
            if(arr_minus[num * -1] == '\0'){
                count++;
                arr_minus[num * -1] = 1;
            }
        }
    });
    
    return count;
}

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.004 s

Code: 15:03:19 UTC, cpp, 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 19 20 21 22 23 24 25 26 27 28 29

// you can use includes, for example:
#include <algorithm>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(vector<int> &A) {
    // write your code in C++14 (g++ 6.2.0)
    
    int count = 0;
    int arr_plus[1000001] = {'\0',};
    int arr_minus[1000001] = {'\0',};
    
    for_each(A.begin(), A.end(),[&](auto& num){
        if(num >= 0){
            if(arr_plus[num] == '\0'){
                count++;
                arr_plus[num] = 1;
            }
        }else{
            if(arr_minus[num * -1] == '\0'){
                count++;
                arr_minus[num * -1] = 1;
            }
        }
    });
    
    return count;
}

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

✔

0.004 s

expand all Correctness tests

▶

extreme_empty
empty sequence

✔

0.001 s

▶

extreme_single
sequence of one element

✔

0.001 s

▶

extreme_two_elems
sequence of three distinct elements

✔

0.001 s

▶

extreme_one_value
sequence of 10 equal elements

✔

0.001 s

▶

extreme_negative
sequence of negative elements, length=5

✔

0.001 s

▶

extreme_big_values
sequence with big values, length=5

✔

0.001 s

▶

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

✔

0.001 s

▶

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

✔

0.004 s

▶

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

✔

0.004 s

expand all Performance tests

▶

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

✔

0.004 s

▶

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

✔

0.008 s

▶

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

✔

0.012 s