Test results - Codility

Tasks Details

easy

1. OddOccurrencesInArray

Find value that occurs in odd number of elements.

Task Score

100%

Correctness

100%

Performance

100%

A non-empty array A consisting of N integers is given. The array contains an odd number of elements, and each element of the array can be paired with another element that has the same value, except for one element that is left unpaired.

For example, in array A such that:

A[0] = 9 A[1] = 3 A[2] = 9 A[3] = 3 A[4] = 9 A[5] = 7 A[6] = 9

the elements at indexes 0 and 2 have value 9,

the elements at indexes 1 and 3 have value 3,

the elements at indexes 4 and 6 have value 9,

the element at index 5 has value 7 and is unpaired.

Write a function:

function solution(A);

that, given an array A consisting of N integers fulfilling the above conditions, returns the value of the unpaired element.

For example, given array A such that:

A[0] = 9 A[1] = 3 A[2] = 9 A[3] = 3 A[4] = 9 A[5] = 7 A[6] = 9

the function should return 7, as explained in the example above.

Write an efficient algorithm for the following assumptions:

N is an odd integer within the range [1..1,000,000];

each element of array A is an integer within the range [1..1,000,000,000];

all but one of the values in A occur an even number of times.

Solution

Programming language used JavaScript

Time spent on task 4 minutes

Notes

not defined yet

Task timeline

Code: 14:15:29 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: 14:15:52 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    
}

Code: 14:16:12 UTC, js, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        console.log(A[i])
    }
}

Analysis

expand all Example tests

▶

example1
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'undefined' found
Perhaps you are missing a 'return'?

stdout:

Code: 14:16:22 UTC, js, autosave

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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        
    }
}

Code: 14:16:33 UTC, js, autosave

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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            map
        }
    }
}

Code: 14:17:00 UTC, js, verify, result: Failed

show code in pop-up

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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(map)
}

Analysis

expand all Example tests

▶

example1
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.076 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'undefined' found
Perhaps you are missing a 'return'?

stdout:

{ '7': true }

Code: 14:17:05 UTC, js, 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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(map)
    
}

Code: 14:17:15 UTC, js, 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.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(map)
    return 
}

Code: 14:17:26 UTC, js, verify, result: Failed

show code in pop-up

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.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(map)
    return Object.keys(map)[0]
}

Analysis

expand all Example tests

▶

example1
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'string' found

stdout:

{ '7': true }

Code: 14:17:34 UTC, js, verify, result: Failed

show code in pop-up

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.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(Object.keys(map))
    return Object.keys(map)[0]
}

Analysis

expand all Example tests

▶

example1
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'string' found

stdout:

[ '7' ]

Code: 14:18:12 UTC, js, 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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(Object.keys(object1))
    return Object.keys(map)[0]
}

Code: 14:18:19 UTC, js, verify, result: Failed

show code in pop-up

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.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(Object.keys(map)[0])
    return Object.keys(map)[0]
}

Analysis

expand all Example tests

▶

example1
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'string' found

stdout:

Code: 14:18:31 UTC, js, 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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    console.log(Object.keys(map)[0])
    return +Object.keys(map)[0]
}

Analysis

expand all Example tests

▶

example1
example test

✔

0.072 s

stdout:

Code: 14:18:37 UTC, js, 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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    return +Object.keys(map)[0]
}

Analysis

expand all Example tests

▶

example1
example test

✔

0.072 s

Code: 14:18:44 UTC, js, 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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    return +Object.keys(map)[0]
}

Analysis

expand all Example tests

▶

example1
example test

✔

0.072 s

Code: 14:18:47 UTC, js, 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

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(A) {
    
    const map = {}
    
    for (let i=0; i <= A.length - 1; i++) {
        const target = A[i]
        if (map[target]) {
            delete map[target]
        } else {
            map[target] = true
        }
    }
    
    return +Object.keys(map)[0]
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N) or O(N*log(N))

expand all Example tests

▶

example1
example test

✔

0.072 s

expand all Correctness tests

▶

simple1
simple test n=5

✔

0.072 s

▶

simple2
simple test n=11

✔

0.068 s

▶

extreme_single_item
[42]

✔

0.072 s

▶

small1
small random test n=201

✔

0.068 s

▶

small2
small random test n=601

✔

0.072 s

expand all Performance tests

▶

medium1
medium random test n=2,001

✔

0.072 s

▶

medium2
medium random test n=100,003

✔

0.144 s

▶

big1
big random test n=999,999, multiple repetitions

✔

0.392 s

▶

big2
big random test n=999,999

✔

0.648 s