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:

class Solution { public int solution(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 Java 8

Time spent on task 6 minutes

Notes

not defined yet

Task timeline

Code: 12:26:29 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: 12:27:05 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) {
        Arrays.sort(A);
        for(int i=0;)
        // write your code in Java SE 8
    }
}

Code: 12:28:48 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) {
        TreeMap map = new TreeMap();
        // write your code in Java SE 8
    }
}

Code: 12:29:11 UTC, java, verify, result: Failed

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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) {
        TreeMap map = new TreeMap();
        for(int i=0; i<A.length; i++){
            map.put(A[i]);
        }
        // write your code in Java SE 8
    }
}

Analysis

Compile error

Solution.java:11: error: no suitable method found for put(int)
            map.put(A[i]);
               ^
    method Map.put(Object,Object) is not applicable
      (actual and formal argument lists differ in length)
    method AbstractMap.put(Object,Object) is not applicable
      (actual and formal argument lists differ in length)
    method TreeMap.put(Object,Object) is not applicable
      (actual and formal argument lists differ in length)
1 error

Code: 12:29:27 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) {
        TreeMap map = new TreeMap();
        for(int i=0; i<A.length; i++){
            map.put(A[i].);
        }
        // write your code in Java SE 8
    }
}

Code: 12:29:30 UTC, java, verify, result: Failed

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

// 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) {
        TreeMap map = new TreeMap();
        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        // write your code in Java SE 8
    }
}

Analysis

Compile error

Solution.java:14: error: missing return statement
    }
    ^
Note: Solution.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error

Code: 12:30:23 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) {
       Map<String, String> testMap = new HashMap<String, String>();

출처: https://bvc12.tistory.com/163 [국브스토리]
        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        // write your code in Java SE 8
    }
}

Code: 12:30:36 UTC, java, verify, result: Failed

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

// 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) {
        Map<Integer, Integer> testMap = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        // write your code in Java SE 8
    }
}

Analysis

Compile error

Solution.java:12: error: cannot find symbol
            map.put(A[i], 1);
            ^
  symbol:   variable map
  location: class Solution
1 error

Code: 12:30:44 UTC, java, verify, result: Failed

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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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        // write your code in Java SE 8
    }
}

Analysis

Compile error

Solution.java:15: error: missing return statement
    }
    ^
1 error

Code: 12:30:53 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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        // write your code in Java SE 8
    }
}

Code: 12:31:04 UTC, java, 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 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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        // write your code in Java SE 8
    }
}

Code: 12:31:15 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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            if(map.contains)
        }
        // write your code in Java SE 8
    }
}

Code: 12:31:43 UTC, java, verify, result: Failed

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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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            if(!map.containsKey(i)){
                return 0;
            }
        }
        
        return 1;
        // write your code in Java SE 8
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✘

WRONG ANSWER
got 0 expected 1

0.004 s

WRONG ANSWER, got 0 expected 1

▶

example2
the second example test

✔

0.004 s

Code: 12:31:56 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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            if(!map.containsKey(i+1)){
                return 0;
            }
        }
        
        return 1;
        // write your code in Java SE 8
    }
}

Code: 12:31:58 UTC, java, verify, result: Passed

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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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            if(!map.containsKey(i+1)){
                return 0;
            }
        }
        
        return 1;
        // write your code in Java SE 8
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✔

0.004 s

Code: 12:32:05 UTC, java, verify, result: Passed

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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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            if(!map.containsKey(i+1)){
                return 0;
            }
        }
        
        return 1;
        // write your code in Java SE 8
    }
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.004 s

▶

example2
the second example test

✔

0.004 s

Code: 12:32:09 UTC, java, final, score: 100

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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

// 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) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();

        for(int i=0; i<A.length; i++){
            map.put(A[i], 1);
        }
        
        for(int i=0; i<A.length; i++){
            if(!map.containsKey(i+1)){
                return 0;
            }
        }
        
        return 1;
        // write your code in Java SE 8
    }
}

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

✔

0.008 s

▶

example2
the second example test

✔

0.008 s

expand all Correctness tests

▶

extreme_min_max
single element with minimal/maximal value

✔

0.008 s

0.004 s

▶

single
single element

✔

0.008 s

▶

double
two elements

✔

0.008 s

0.004 s

0.008 s

▶

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

✔

0.004 s

0.008 s

0.004 s

0.008 s

▶

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

✔

0.008 s

▶

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

✔

0.004 s

0.008 s

expand all Performance tests

▶

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

✔

0.048 s

▶

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

✔

0.380 s

0.376 s

▶

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

✔

0.484 s

▶

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

✔

0.476 s

0.480 s

▶

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

✔

0.008 s

0.228 s

0.008 s

▶

various_permutations
all sequences are permutations

✔

0.004 s

0.008 s

0.048 s

0.472 s

0.484 s