Test results - Codility

Tasks Details

easy

1. TapeEquilibrium

Minimize the value |(A[0] + ... + A[P-1]) - (A[P] + ... + A[N-1])|.

Task Score

100%

Correctness

100%

Performance

100%

A non-empty array A consisting of N integers is given. Array A represents numbers on a tape.

Any integer P, such that 0 < P < N, splits this tape into two non-empty parts: A[0], A[1], ..., A[P − 1] and A[P], A[P + 1], ..., A[N − 1].

The difference between the two parts is the value of: |(A[0] + A[1] + ... + A[P − 1]) − (A[P] + A[P + 1] + ... + A[N − 1])|

In other words, it is the absolute difference between the sum of the first part and the sum of the second part.

For example, consider array A such that:

A[0] = 3 A[1] = 1 A[2] = 2 A[3] = 4 A[4] = 3

We can split this tape in four places:

P = 1, difference = |3 − 10| = 7

P = 2, difference = |4 − 9| = 5

P = 3, difference = |6 − 7| = 1

P = 4, difference = |10 − 3| = 7

Write a function:

function solution(A);

that, given a non-empty array A of N integers, returns the minimal difference that can be achieved.

For example, given:

A[0] = 3 A[1] = 1 A[2] = 2 A[3] = 4 A[4] = 3

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 [−1,000..1,000].

Solution

Programming language used JavaScript

Time spent on task 9 minutes

Notes

not defined yet

Task timeline

Code: 08:34:09 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: 08:36:24 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: 08:36:46 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)
    let P = 1;

    
}

Code: 08:37:03 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)
    let P = 1;
    let min = 
    while(true){

    }

}

Code: 08:37:50 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)
    let P = 1;
    let min = Nu
    while(true){

    }

}

Code: 08:38:02 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)
    let P = 1;
    let min = Number.MAX_SAFE_INTEGER;
    while(true){
        
    }

}

Code: 08:38:12 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)
    let P = 1;
    let min = Number.MAX_SAFE_INTEGER;
    
    while(true){

    }

}

Code: 08:38:43 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)
    let P = 1;
    let min = Number.MAX_SAFE_INTEGER;
    let leftSum = 0;
    let rightSum = 0;

    for(let i=0;i<A.length;i++){
        
    }

    while(true){

    }

}

Code: 08:39:03 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)
    let P = 1;
    let min = Number.MAX_SAFE_INTEGER;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        
    })

    while(true){

    }

}

Code: 08:39:31 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)
    let P = 1;
    let min = Number.MAX_SAFE_INTEGER;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    while(true){

    }

}

Code: 08:39:41 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)
    let P = 1;
    let min = Number.MAX_SAFE_INTEGER;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    

    while(true){

    }

}

Code: 08:40:01 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(true){
        
    }

}

Code: 08:40:17 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length){

    }

}

Code: 08:40:27 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

// 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        
    }

}

Code: 08:40:37 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        P++;
        
    }

}

Code: 08:40:49 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        
        
    }

}

Code: 08:41:08 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        
    }

}

Code: 08:41:38 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

// 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        min = Math.min(min, Math.abs(leftSum-rightSum));
        P++;
    }

}

Code: 08:41:44 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) {
    // write your code in JavaScript (Node.js 8.9.4)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        min = Math.min(min, Math.abs(leftSum-rightSum));
        P++;
    }
    return min;
}

Analysis

expand all Example tests

▶

example
example test

✔

0.068 s

Code: 08:42:05 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 20 21 22 23 24 25 26 27

// 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        min = Math.min(min, Math.abs(leftSum-rightSum));
        P++;
    }
    return min;
}

Code: 08:42:05 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 20 21 22 23 24 25 26 27

// 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        min = Math.min(min, Math.abs(leftSum-rightSum));
        P++;
    }
    return min;
}

User test case 1:

[1, 2, 3]

Analysis

expand all Example tests

▶

example
example test

✔

0.072 s

expand all User tests

▶

test_data1

✔

0.072 s

OK
function result: 0

Code: 08:42:22 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) {
    // write your code in JavaScript (Node.js 8.9.4)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        min = Math.min(min, Math.abs(leftSum-rightSum));
        P++;
    }
    return min;
}

User test case 1:

[1, 2, 3]

Analysis

expand all Example tests

▶

example
example test

✔

0.072 s

expand all User tests

▶

test_data1

✔

0.096 s

OK
function result: 0

Code: 08:42:25 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 19 20 21 22 23 24 25 26 27

// 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)
    let P = 1;
    let leftSum = 0;
    let rightSum = 0;

    A.forEach((val, idx) => {
        if(idx < P){
            leftSum += val;
        }else{
            rightSum += val;
        }
    });

    let min = Math.abs(leftSum - rightSum);

    while(P < A.length-1){
        leftSum += A[P];
        rightSum -= A[P];
        min = Math.min(min, Math.abs(leftSum-rightSum));
        P++;
    }
    return min;
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example
example test

✔

0.072 s

expand all Correctness tests

▶

double
two elements

✔

0.072 s

0.068 s

0.072 s

▶

simple_positive
simple test with positive numbers, length = 5

✔

0.072 s

▶

simple_negative
simple test with negative numbers, length = 5

✔

0.072 s

▶

simple_boundary
only one element on one of the sides

✔

0.072 s

0.068 s

▶

small_random
random small, length = 100

✔

0.068 s

▶

small_range
range sequence, length = ~1,000

✔

0.072 s

▶

small
small elements

✔

0.068 s

expand all Performance tests

▶

medium_random1
random medium, numbers from 0 to 100, length = ~10,000

✔

0.084 s

▶

medium_random2
random medium, numbers from -1,000 to 50, length = ~10,000

✔

0.088 s

▶

large_ones
large sequence, numbers from -1 to 1, length = ~100,000

✔

0.104 s

0.108 s

▶

large_random
random large, length = ~100,000

✔

0.112 s

0.116 s

▶

large_sequence
large sequence, length = ~100,000

✔

0.100 s

▶

large_extreme
large test with maximal and minimal values, length = ~100,000

✔

0.116 s

0.112 s

0.108 s