Test results - Codility

Tasks Details

medium

1. MinAvgTwoSlice

Find the minimal average of any slice containing at least two elements.

Task Score

20%

Correctness

40%

Performance

A non-empty array A consisting of N integers is given. A pair of integers (P, Q), such that 0 ≤ P < Q < N, is called a slice of array A (notice that the slice contains at least two elements). The average of a slice (P, Q) is the sum of A[P] + A[P + 1] + ... + A[Q] divided by the length of the slice. To be precise, the average equals (A[P] + A[P + 1] + ... + A[Q]) / (Q − P + 1).

For example, array A such that:

A[0] = 4 A[1] = 2 A[2] = 2 A[3] = 5 A[4] = 1 A[5] = 5 A[6] = 8

contains the following example slices:

slice (1, 2), whose average is (2 + 2) / 2 = 2;

slice (3, 4), whose average is (5 + 1) / 2 = 3;

slice (1, 4), whose average is (2 + 2 + 5 + 1) / 4 = 2.5.

The goal is to find the starting position of a slice whose average is minimal.

Write a function:

function solution(A);

that, given a non-empty array A consisting of N integers, returns the starting position of the slice with the minimal average. If there is more than one slice with a minimal average, you should return the smallest starting position of such a slice.

For example, given array A such that:

A[0] = 4 A[1] = 2 A[2] = 2 A[3] = 5 A[4] = 1 A[5] = 5 A[6] = 8

the function should return 1, as explained above.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [2..100,000];

each element of array A is an integer within the range [−10,000..10,000].

Solution

Programming language used JavaScript

Time spent on task 17 minutes

Notes

not defined yet

Code: 05:25:38 UTC, js, verify, result: Failed

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

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j).reduce(function (a,b) { return a+b }) / (j - i)
            if ( m === null || c < m ) {
                m = c
                n = i
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got 4 expected 1

0.117 s

WRONG ANSWER, got 4 expected 1

Code: 05:27:40 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');

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j).reduce(function (a,b) { return a+b }) / (j - i + 1)
            if ( m === null || c < m ) {
                m = c
                n = i
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got 4 expected 1

0.113 s

WRONG ANSWER, got 4 expected 1

Code: 05:28:01 UTC, js, 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

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

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            if ( m === null || c < m ) {
                m = c
                n = i
            }
        }
    }
    return n
}

Analysis

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▶

example
example test

✔

0.116 s

Code: 05:28:49 UTC, js, verify, result: Failed

show code in pop-up

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

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

function solution(A) {
    var m = null, c, n = null
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            if ( m === null || c <= m ) {
                m = c
                if ( n === null || i < n ) {
                    n = i
                }
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got 0 expected 1

0.116 s

WRONG ANSWER, got 0 expected 1

Code: 05:29:15 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 20 21

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

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

function solution(A) {
    var m = null, c, n = null
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            if ( m === null || c <= m ) {
                m = c
                if ( n === null || i < n ) {
                    n = i
                }
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got 0 expected 1

0.113 s

WRONG ANSWER, got 0 expected 1

Code: 05:30:11 UTC, js, verify, result: Failed

show code in pop-up

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

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

function solution(A) {
    var m = null, c, n = null
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            console.log({i, j, c, m, n})
            if ( m === null || c <= m ) {
                m = c
                if ( n === null || i < n ) {
                    n = i
                }
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got 0 expected 1

0.161 s

WRONG ANSWER, got 0 expected 1

stdout:

{ i: 0, j: 1, c: 3, m: null, n: null }
{ i: 0, j: 2, c: 2.6666666666666665, m: 3, n: 0 }
{ i: 0, j: 3, c: 3.25, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 4, c: 2.8, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 5, c: 3.1666666666666665, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 6, c: 3.857142857142857, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 7, c: 3.375, m: 2.6666666666666665, n: 0 }
{ i: 1, j: 2, c: 2, m: 2.6666666666666665, n: 0 }
{ i: 1, j: 3, c: 3, m: 2, n: 0 }
{ i: 1, j: 4, c: 2.5, m: 2, n: 0 }
{ i: 1, j: 5, c: 3, m: 2, n: 0 }
{ i: 1, j: 6, c: 3.8333333333333335, m: 2, n: 0 }
{ i: 1, j: 7, c: 3.2857142857142856, m: 2, n: 0 }
{ i: 2, j: 3, c: 3.5, m: 2, n: 0 }
{ i: 2, j: 4, c: 2.6666666666666665, m: 2, n: 0 }
{ i: 2, j: 5, c: 3.25, m: 2, n: 0 }
{ i: 2, j: 6, c: 4.2, m: 2, n: 0 }
{ i: 2, j: 7, c: 3.5, m: 2, n: 0 }
{ i: 3, j: 4, c: 3, m: 2, n: 0 }
{ i: 3, j: 5, c: 3.6666666666666665, m: 2, n: 0 }
{ i: 3, j: 6, c: 4.75, m: 2, n: 0 }
{ i: 3, j: 7, c: 3.8, m: 2, n: 0 }
{ i: 4, j: 5, c: 3, m: 2, n: 0 }
{ i: 4, j: 6, c: 4.666666666666667, m: 2, n: 0 }
{ i: 4, j: 7, c: 3.5, m: 2, n: 0 }
{ i: 5, j: 6, c: 6.5, m: 2, n: 0 }
{ i: 5, j: 7, c: 4.333333333333333, m: 2, n: 0 }
{ i: 6, j: 7, c: 4, m: 2, n: 0 }

Code: 05:31:34 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 20 21 22

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

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            console.log({i, j, c, m, n})
            if ( m === null || c <= m ) {
                m = c
                if ( c < m || i < n ) {
                    n = i
                }
            }
        }
    }
    return n
}

Analysis

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▶

example
example test

✘

RUNTIME ERROR
tested program terminated unexpectedly

0.154 s

RUNTIME ERROR, tested program terminated unexpectedly

stderr:

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

stdout:

{ i: 0, j: 1, c: 3, m: null, n: undefined }
{ i: 0, j: 2, c: 2.6666666666666665, m: 3, n: undefined }
{ i: 0, j: 3, c: 3.25, m: 2.6666666666666665, n: undefined }
{ i: 0, j: 4, c: 2.8, m: 2.6666666666666665, n: undefined }
{ i: 0,
  j: 5,
  c: 3.1666666666666665,
  m: 2.6666666666666665,
  n: undefined }
{ i: 0,
  j: 6,
  c: 3.857142857142857,
  m: 2.6666666666666665,
  n: undefined }
{ i: 0, j: 7, c: 3.375, m: 2.6666666666666665, n: undefined }
{ i: 1, j: 2, c: 2, m: 2.6666666666666665, n: undefined }
{ i: 1, j: 3, c: 3, m: 2, n: undefined }
{ i: 1, j: 4, c: 2.5, m: 2, n: undefined }
{ i: 1, j: 5, c: 3, m: 2, n: undefined }
{ i: 1, j: 6, c: 3.8333333333333335, m: 2, n: undefined }
{ i: 1, j: 7, c: 3.2857142857142856, m: 2, n: undefined }
{ i: 2, j: 3, c: 3.5, m: 2, n: undefined }
{ i: 2, j: 4, c: 2.6666666666666665, m: 2, n: undefined }
{ i: 2, j: 5, c: 3.25, m: 2, n: undefined }
{ i: 2, j: 6, c: 4.2, m: 2, n: undefined }
{ i: 2, j: 7, c: 3.5, m: 2, n: undefined }
{ i: 3, j: 4, c: 3, m: 2, n: undefined }
{ i: 3, j: 5, c: 3.6666666666666665, m: 2, n: undefined }
{ i: 3, j: 6, c: 4.75, m: 2, n: undefined }
{ i: 3, j: 7, c: 3.8, m: 2, n: undefined }
{ i: 4, j: 5, c: 3, m: 2, n: undefined }
{ i: 4, j: 6, c: 4.666666666666667, m: 2, n: undefined }
{ i: 4, j: 7, c: 3.5, m: 2, n: undefined }
{ i: 5, j: 6, c: 6.5, m: 2, n: undefined }
{ i: 5, j: 7, c: 4.333333333333333, m: 2, n: undefined }
{ i: 6, j: 7, c: 4, m: 2, n: undefined }

Code: 05:32:46 UTC, js, verify, result: Passed

show code in pop-up

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

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            console.log({i, j, c, m, n})
            if ( m === null || c < m ) {
                m = c
                n = i
            }
            else if ( c == m && i < n ) {
                n = i
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✔

0.162 s

stdout:

{ i: 0, j: 1, c: 3, m: null, n: undefined }
{ i: 0, j: 2, c: 2.6666666666666665, m: 3, n: 0 }
{ i: 0, j: 3, c: 3.25, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 4, c: 2.8, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 5, c: 3.1666666666666665, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 6, c: 3.857142857142857, m: 2.6666666666666665, n: 0 }
{ i: 0, j: 7, c: 3.375, m: 2.6666666666666665, n: 0 }
{ i: 1, j: 2, c: 2, m: 2.6666666666666665, n: 0 }
{ i: 1, j: 3, c: 3, m: 2, n: 1 }
{ i: 1, j: 4, c: 2.5, m: 2, n: 1 }
{ i: 1, j: 5, c: 3, m: 2, n: 1 }
{ i: 1, j: 6, c: 3.8333333333333335, m: 2, n: 1 }
{ i: 1, j: 7, c: 3.2857142857142856, m: 2, n: 1 }
{ i: 2, j: 3, c: 3.5, m: 2, n: 1 }
{ i: 2, j: 4, c: 2.6666666666666665, m: 2, n: 1 }
{ i: 2, j: 5, c: 3.25, m: 2, n: 1 }
{ i: 2, j: 6, c: 4.2, m: 2, n: 1 }
{ i: 2, j: 7, c: 3.5, m: 2, n: 1 }
{ i: 3, j: 4, c: 3, m: 2, n: 1 }
{ i: 3, j: 5, c: 3.6666666666666665, m: 2, n: 1 }
{ i: 3, j: 6, c: 4.75, m: 2, n: 1 }
{ i: 3, j: 7, c: 3.8, m: 2, n: 1 }
{ i: 4, j: 5, c: 3, m: 2, n: 1 }
{ i: 4, j: 6, c: 4.666666666666667, m: 2, n: 1 }
{ i: 4, j: 7, c: 3.5, m: 2, n: 1 }
{ i: 5, j: 6, c: 6.5, m: 2, n: 1 }
{ i: 5, j: 7, c: 4.333333333333333, m: 2, n: 1 }
{ i: 6, j: 7, c: 4, m: 2, n: 1 }

Code: 05:32:58 UTC, js, verify, result: Passed

show code in pop-up

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

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            if ( m === null || c < m ) {
                m = c
                n = i
            }
            else if ( c == m && i < n ) {
                n = i
            }
        }
    }
    return n
}

Analysis

expand all Example tests

▶

example
example test

✔

0.086 s

Code: 05:33:01 UTC, js, final, score: 20

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

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

function solution(A) {
    var m = null, c, n
    for ( var i = 0; i < A.length; ++i ) {
        for ( var j = i + 1; j <= A.length; ++j ) {
            c = A.slice(i, j + 1).reduce(function (a,b) { return a+b }) / (j - i + 1)
            if ( m === null || c < m ) {
                m = c
                n = i
            }
            else if ( c == m && i < n ) {
                n = i
            }
        }
    }
    return n
}

Analysis summary

The following issues have been detected: wrong answers, timeout errors.

For example, for the input [10000, -10000] the solution returned a wrong answer (got 1 expected 0).

Analysis

expand all Example tests

▶

example
example test

✔

0.116 s

expand all Correctness tests

▶

double_quadruple
two or four elements

✘

WRONG ANSWER
got 1 expected 0

0.113 s

0.112 s

WRONG ANSWER, got 1 expected 0

0.111 s

WRONG ANSWER, got 1 expected 0

0.115 s

▶

simple1
simple test, the best slice has length 3

✘

WRONG ANSWER
got 7 expected 5

0.110 s

0.114 s

WRONG ANSWER, got 7 expected 5

▶

simple2
simple test, the best slice has length 3

✔

0.116 s

▶

small_random
random, length = 100

✔

0.129 s

▶

medium_range
increasing, decreasing (legth = ~100) and small functional

✘

WRONG ANSWER
got 101 expected 100

0.129 s

0.128 s

WRONG ANSWER, got 101 expected 100

0.115 s

WRONG ANSWER, got 12 expected 3

expand all Performance tests

▶

medium_random
random, N = ~700

✘

TIMEOUT ERROR
running time: 1.54 sec., time limit: 0.48 sec.

1.542 s

TIMEOUT ERROR, running time: 1.54 sec., time limit: 0.48 sec.

▶

large_ones
numbers from -1 to 1, N = ~100,000

✘

TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.73 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.73 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.67 sec.

▶

large_random
random, N = ~100,000

✘

TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.77 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.77 sec.

▶

extreme_values
all maximal values, N = ~100,000

✘

TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.76 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.76 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.78 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.77 sec.

▶

large_sequence
many seqeneces, N = ~100,000

✘

TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.70 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.70 sec.

6.000 s

TIMEOUT ERROR, running time: >6.00 sec., time limit: 0.71 sec.