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(vector<int> &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 C++

Time spent on task 9 minutes

Notes

not defined yet

Task timeline

Code: 03:49:36 UTC, java, autosave

show code in pop-up

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long sum_tot = len*(len+1)/2;
    long long sum_A = 0;
    
    // 
    if(len == 1){
        if(A[0] == 1){
            return 1;
        }else{
            return 0;
        }
    }

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt ++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:49:58 UTC, java, autosave

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#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long sum_tot = len*(len+1)/2;
    long long sum_A = 0;
    
    // 
    if(len == 1){
        if(A[0] == 1){
            return 1;
        }else{
            return 0;
        }
    }

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt ++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:50:15 UTC, cpp, autosave

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;
    
    // 
    if(len == 1){
        if(A[0] == 1){
            return 1;
        }else{
            return 0;
        }
    }

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt ++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:50:28 UTC, cpp, autosave

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;
    
    // 
    if(len == 1){
        if(A[0] == 1){
            return 1;
        }else{
            return 0;
        }
    }

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:52:39 UTC, cpp, autosave

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;
    

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:52:50 UTC, cpp, autosave

show code in pop-up

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:55:06 UTC, cpp, autosave

show code in pop-up

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;

    
    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:55:25 UTC, cpp, autosave

show code in pop-up

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;
    vector<int> check(len+1, 0);

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;

    // sort
    sort(A.begin(), A.end());
    
    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:56:06 UTC, cpp, autosave

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;

    // 전체 sum_tot
    long long int sum_tot = len*(len+1)/2;
    long long int sum_A = 0;

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:56:17 UTC, cpp, autosave

show code in pop-up

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        sum_A += A[i];
        if(check[A[i]] == 0){
            check[A[i]] = 1;
            cnt++;
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:56:30 UTC, cpp, autosave

show code in pop-up

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(check[i] == 0){
        }
    }

    if((sum_A == sum_tot) && (cnt == len)){
        return 1;
    }else{
        return 0;
    }
    
}

Code: 03:56:53 UTC, cpp, verify, result: Failed

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();
    int cnt = 0;

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(check[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

Analysis

Compile error

func.cpp:1:1: error: expected unqualified-id before '/' token
 / you can use includes, for example:
 ^
func.cpp: In function 'int solution(std::vector<int>&)':
func.cpp:16:12: error: 'check' was not declared in this scope
         if(check[i] == i+1){
            ^~~~~
func.cpp:10:9: warning: unused variable 'cnt' [-Wunused-variable]
     int cnt = 0;
         ^~~

Code: 03:57:01 UTC, cpp, autosave

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(check[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

Code: 03:57:03 UTC, cpp, verify, result: Failed

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(check[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

Analysis

Compile error

func.cpp:1:1: error: expected unqualified-id before '/' token
 / you can use includes, for example:
 ^
func.cpp: In function 'int solution(std::vector<int>&)':
func.cpp:15:12: error: 'check' was not declared in this scope
         if(check[i] == i+1){
            ^~~~~

Code: 03:57:09 UTC, cpp, verify, result: Failed

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/ you can use includes, for example:
#include <bits/stdc++.h>

// 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 len = A.size();

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(A[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

Analysis

Compile error

func.cpp:1:1: error: expected unqualified-id before '/' token
 / you can use includes, for example:
 ^

Code: 03:57:22 UTC, cpp, verify, result: Passed

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#include <bits/stdc++.h>

// 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 len = A.size();

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(A[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.001 s

▶

example2
the second example test

✔

0.001 s

Code: 03:57:29 UTC, cpp, verify, result: Passed

show code in pop-up

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#include <bits/stdc++.h>

// 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 len = A.size();

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(A[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.001 s

▶

example2
the second example test

✔

0.001 s

Code: 03:57:34 UTC, cpp, final, score: 100

show code in pop-up

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#include <bits/stdc++.h>

// 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 len = A.size();

    // sort
    sort(A.begin(), A.end());

    for(int i=0; i<len; i++){
        if(A[i] == i+1){
            continue;
        }else{
            return 0;
        }
    }

    return 1;
    
}

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

✔

0.008 s

0.012 s

▶

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

✔

0.012 s

▶

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

✔

0.008 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

0.012 s