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:

int solution(int A[], int N);

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 C

Time spent on task 31 minutes

Notes

not defined yet

Task timeline

Code: 00:05:54 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: 00:06:47 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
}

Code: 00:06:52 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    sum = 1 + N;
    quo = N/2;
    
    
    if(N%2 == 0)
        sum = sum * quo;
    else
        sum = (sum * quo) + quo + 1;
    
    for(i = 0; i < N; i++)
        sum -= A[i];
        
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:17:39 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    sum = 1 + N;
    quo = N/2;

    for(i = 0; i < N; i++)
        sum -= A[i];
        
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:17:55 UTC, c, autosave

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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
   for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:21:50 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
   for(i = 0; i < N; i++)
        sum ^= A[i];
        
    i
    
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:22:01 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
   for(i = 0; i < N; i++)
        sum ^= A[i];
        
    if()
    
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:22:15 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/2
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:22:31 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    
    
    if(sum == 0)
        return 1;
    else
        return 0;
    
}

Code: 00:23:01 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    swi
    
    
    
    
}

Code: 00:23:12 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    switch()
    
    
    
    
}

Code: 00:23:23 UTC, c, autosave

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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    switch(ren)
    
    
    
    
}

Code: 00:23:41 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    switch(ren){
        case 0:
        
    }
    
    
    
    
}

Code: 00:26:20 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    switch(ren){
        case 0:
        
    }
    
    
    
    
}

Code: 00:26:31 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    switch(ren){
        case 0:
        
    }
    
    
    
    
}

Code: 00:32:03 UTC, c, autosave

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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    
    
    
    
}

Code: 00:32:16 UTC, c, autosave

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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && )
    
    
    
    
}

Code: 00:32:37 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo)
    
    
    
    
}

Code: 00:33:01 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 )
    
    
    
    
}

Code: 00:33:10 UTC, c, 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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
    
    
    
    
}

Code: 00:34:55 UTC, c, autosave

show code in pop-up

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        
    
    
    
}

Code: 00:35:09 UTC, c, 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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren ==2 && )
    
    
    
}

Code: 00:35:20 UTC, c, autosave

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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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren ==2 && sum == )
    
    
    
}

Code: 00:35:36 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren ==2 && sum == quo)
    
    
    
}

Code: 00:35:58 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren ==2 && sum == ((quo + 1) * 4) -1 )
    
    
    
}

Code: 00:36:29 UTC, c, autosave

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren == 2 && sum == ((quo + 1) * 4) - 1 )
        return 1;
    else if(ren == 3 && sum == )
    
    
}

Code: 00:36:44 UTC, c, verify, result: Passed

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// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren == 2 && sum == ((quo + 1) * 4) - 1 )
        return 1;
    else if(ren == 3 && sum == 0)
        return 1;
    else
        return 0;
    
    
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.001 s

▶

example2
the second example test

✔

0.001 s

Code: 00:36:49 UTC, c, 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 19 20 21 22 23 24 25 26 27

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren == 2 && sum == ((quo + 1) * 4) - 1 )
        return 1;
    else if(ren == 3 && sum == 0)
        return 1;
    else
        return 0;
    
    
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.001 s

▶

example2
the second example test

✔

0.001 s

Code: 00:36:50 UTC, c, 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

// you can write to stdout for debugging purposes, e.g.
// printf("this is a debug message\n");

int solution(int A[], int N) {
    // write your code in C99 (gcc 6.2.0)
    int i, quo, ren, sum = 0;
    
    quo = N/4;
    ren = N%4;
    
    for(i = 0; i < N; i++)
        sum ^= A[i];
        
    
    if(ren == 0 && sum == quo * 4)
        return 1;
    else if(ren == 1 && sum == 1)
        return 1;
    else if(ren == 2 && sum == ((quo + 1) * 4) - 1 )
        return 1;
    else if(ren == 3 && sum == 0)
        return 1;
    else
        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

✔

0.001 s

▶

example2
the second example test

✔

0.001 s

expand all Correctness tests

▶

extreme_min_max
single element with minimal/maximal value

✔

0.001 s

▶

single
single element

✔

0.001 s

▶

double
two elements

✔

0.001 s

▶

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

✔

0.001 s

▶

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

✔

0.001 s

▶

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

✔

0.001 s

expand all Performance tests

▶

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

✔

0.001 s

▶

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

✔

0.004 s

▶

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

✔

0.004 s

▶

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

✔

0.004 s

▶

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

✔

0.001 s

0.004 s

0.001 s

▶

various_permutations
all sequences are permutations

✔

0.001 s

0.004 s