Test results - Codility

Tasks Details

medium

1. MinAvgTwoSlice

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

Task Score

100%

Correctness

100%

Performance

100%

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 18 minutes

Notes

not defined yet

Task timeline

Code: 13:44:56 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) {
        // write your code in Java SE 8
    }
}

Code: 13:50:18 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) {
    // write your code in JavaScript (Node.js 8.9.4)
}

Code: 13:52:16 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) {
    // c
}

Code: 13:52:28 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    
}

Code: 13:52:59 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    for (let i=0; i < A.length; i++) {
        
    }
}

Code: 13:53:27 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    let min = (A[0] + A[1]) / 2
    
    for (let i=0; i < A.length; i++) {
        
    }
}

Code: 13:53:38 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    
    for (let i=0; i < A.length; i++) {
        
    }
}

Code: 13:57:03 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    ㅣㄷ
    for (let i=0; i < A.length; i++) {
        
    }
}

Code: 13:57:16 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        
        
    }
}

Code: 13:57:47 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = A[i] + A[i + 1] / 2
        
    }
}

Code: 13:57:57 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        
        
    }
}

Code: 13:58:23 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            
        }
        
    }
}

Code: 13:58:54 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
        }
        
        if (i + 2 <)
        
    }
}

Code: 13:59:07 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum
        }
        
    }
}

Code: 13:59:29 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = 
        }
        
    }
}

Code: 13:59:39 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 2
        }
        
    }
}

Code: 13:59:53 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 2
            
            if (in)
        }
        
    }
}

Code: 14:00:14 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 2
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
        
    }
}

Code: 14:00:53 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 20 21 22 23 24 25 26 27 28 29

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

function solution(A) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 2
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
        
        retur
    }
}

Code: 14:01:00 UTC, js, verify, result: Passed

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

function solution(A) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 2
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
    }
    
    return minIndex
}

Analysis

expand all Example tests

▶

example
example test

✔

0.100 s

Code: 14:01:18 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) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 3
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
    }
    
    return minIndex
}

Code: 14:02:07 UTC, js, verify, result: Passed

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

function solution(A) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 3
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
    }
    
    return minIndex
}

Analysis

expand all Example tests

▶

example
example test

✔

0.072 s

Code: 14:02:12 UTC, js, verify, result: Passed

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

function solution(A) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 3
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
    }
    
    return minIndex
}

Analysis

expand all Example tests

▶

example
example test

✔

0.068 s

Code: 14:02:14 UTC, js, final, score: 100

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

function solution(A) {
    // 최소값은 언제나 두개 혹은 세개로 이루어진 배열이다.
    
    let min = (A[0] + A[1]) / 2
    let minIndex = 0
    for (let i=0; i < A.length - 1; i++) {
        
        let twoSum = (A[i] + A[i + 1]) / 2
        
        if (min > twoSum) {
            min = twoSum
            minIndex = i
        }
        
        if (i + 2 <= A.length - 1) {
            let threeSum = (A[i] + A[i + 1] + A[i + 2]) / 3
            
            if (min > threeSum) {
                min = threeSum
                minIndex = i
            }
        }
    }
    
    return minIndex
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example
example test

✔

0.068 s

expand all Correctness tests

▶

double_quadruple
two or four elements

✔

0.068 s

0.072 s

▶

simple1
simple test, the best slice has length 3

✔

0.068 s

▶

simple2
simple test, the best slice has length 3

✔

0.072 s

▶

small_random
random, length = 100

✔

0.072 s

▶

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

✔

0.068 s

expand all Performance tests

▶

medium_random
random, N = ~700

✔

0.068 s

▶

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

✔

0.100 s

0.096 s

▶

large_random
random, N = ~100,000

✔

0.112 s

▶

extreme_values
all maximal values, N = ~100,000

✔

0.108 s

0.112 s

▶

large_sequence
many seqeneces, N = ~100,000

✔

0.100 s