Test results - Codility

Tasks Details

medium

1. MaxCounters

Calculate the values of counters after applying all alternating operations: increase counter by 1; set value of all counters to current maximum.

Task Score

100%

Correctness

100%

Performance

100%

You are given N counters, initially set to 0, and you have two possible operations on them:

increase(X) − counter X is increased by 1,

max counter − all counters are set to the maximum value of any counter.

A non-empty array A of M integers is given. This array represents consecutive operations:

if A[K] = X, such that 1 ≤ X ≤ N, then operation K is increase(X),

if A[K] = N + 1 then operation K is max counter.

For example, given integer N = 5 and array A such that:

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

the values of the counters after each consecutive operation will be:

(0, 0, 1, 0, 0) (0, 0, 1, 1, 0) (0, 0, 1, 2, 0) (2, 2, 2, 2, 2) (3, 2, 2, 2, 2) (3, 2, 2, 3, 2) (3, 2, 2, 4, 2)

The goal is to calculate the value of every counter after all operations.

Write a function:

function solution(N, A);

that, given an integer N and a non-empty array A consisting of M integers, returns a sequence of integers representing the values of the counters.

Result array should be returned as an array of integers.

For example, given:

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

the function should return [3, 2, 2, 4, 2], as explained above.

Write an efficient algorithm for the following assumptions:

N and M are integers within the range [1..100,000];

each element of array A is an integer within the range [1..N + 1].

Solution

Programming language used JavaScript

Time spent on task 14 minutes

Notes

not defined yet

Task timeline

Code: 09:20:19 UTC, java, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11

// 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 N, int[] A) {
        // write your code in Java SE 8
    }
}

Code: 09:20:19 UTC, java, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11

// 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 N, int[] A) {
        // write your code in Java SE 8
    }
}

Code: 09:20:30 UTC, js, autosave

show code in pop-up

1 2 3

function solution(N, A) {
    
}

Code: 09:20:43 UTC, js, autosave

show code in pop-up

1 2 3 4

function solution(N, A) {
    let max = 0;
    
}

Code: 09:21:59 UTC, js, autosave

show code in pop-up

1 2 3 4 5

function solution(N, A) {
    let max = 0;

    
}

Code: 09:22:10 UTC, js, autosave

show code in pop-up

1 2 3 4 5

function solution(N, A) {
    let max = 0;
    const 
    
}

Code: 09:22:30 UTC, js, autosave

show code in pop-up

1 2 3 4 5

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    
}

Code: 09:22:50 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);

    const maxCounterTarget = [];

    
}

Code: 09:23:04 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    const maxCounterTarget = [];

    A.forEach(num => {
        
    })
}

Code: 09:27:30 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    

    A.forEach(num => {

    })
}

Code: 09:27:54 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        
    })
}

Code: 09:28:24 UTC, js, autosave

show code in pop-up

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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            
        }else{

        }
    })
}

Code: 09:28:39 UTC, js, autosave

show code in pop-up

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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            
        }
    })
}

Code: 09:28:55 UTC, js, autosave

show code in pop-up

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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            
        }
    })
}

Code: 09:29:26 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax)
                counter[idx] = preMax;

            
        }
    })
}

Code: 09:29:54 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax)
                counter[idx] = preMax;

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })
}

Code: 09:29:58 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax)
                counter[idx] = preMax;

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })
}

Analysis

expand all Example tests

▶

example
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, Array expected, 'undefined' found
Perhaps you are missing a 'return'?

Code: 09:30:09 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax)
                counter[idx] = preMax;

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got [3, 0, 1, 4, 0] expected [3, 2, 2, 4, 2]

0.072 s

WRONG ANSWER, got [3, 0, 1, 4, 0] expected [3, 2, 2, 4, 2]

Code: 09:30:40 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){}
                counter[idx] = preMax;

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    return counter;
}

Code: 09:30:49 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got [3, 0, 1, 4, 0] expected [3, 2, 2, 4, 2]

0.068 s

WRONG ANSWER, got [3, 0, 1, 4, 0] expected [3, 2, 2, 4, 2]

Code: 09:31:12 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 20 21 22 23

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        counter
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    return counter;
}

Code: 09:31:19 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 20 21 22 23

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        console.log(counter);
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got [3, 0, 1, 4, 0] expected [3, 2, 2, 4, 2]

0.076 s

WRONG ANSWER, got [3, 0, 1, 4, 0] expected [3, 2, 2, 4, 2]

stdout:

[ 0, 0, 0, 0, 0 ]
[ 0, 0, 1, 0, 0 ]
[ 0, 0, 1, 1, 0 ]
[ 0, 0, 1, 2, 0 ]
[ 0, 0, 1, 2, 0 ]
[ 3, 0, 1, 2, 0 ]
[ 3, 0, 1, 3, 0 ]

Code: 09:32:15 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        console.log(counter);
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })
    

    return counter;
}

Code: 09:32:25 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

function solution(N, A) {
    let max = 0;
    const counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        console.log(counter);
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = 

    return counter;
}

Code: 09:32:55 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        console.log(counter);
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val < preMax)? preMax: val)

    return counter;
}

Code: 09:33:00 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        console.log(counter);
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val < preMax)? preMax: val);

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✔

0.076 s

stdout:

[ 0, 0, 0, 0, 0 ]
[ 0, 0, 1, 0, 0 ]
[ 0, 0, 1, 1, 0 ]
[ 0, 0, 1, 2, 0 ]
[ 0, 0, 1, 2, 0 ]
[ 3, 0, 1, 2, 0 ]
[ 3, 0, 1, 3, 0 ]

Code: 09:33:11 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val < preMax)? preMax: val);

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✔

0.068 s

Code: 09:33:22 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val > preMax)? preMax: val);

    return counter;
}

Code: 09:33:32 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val > preMax)? val: preMax);

    return counter;
}

Code: 09:33:34 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val > preMax)? val: preMax);

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✔

0.072 s

Code: 09:33:38 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val > preMax)? val: preMax);

    return counter;
}

Analysis

expand all Example tests

▶

example
example test

✔

0.068 s

Code: 09:33:41 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

function solution(N, A) {
    let max = 0;
    let counter = new Array(N).fill(0);
    let preMax = 0;
    let currMax = 0;

    A.forEach(num => {
        if(num == N+1){
            preMax = currMax;
        }else{
            const idx = num-1;
            if(counter[idx] < preMax){
                counter[idx] = preMax;
            }

            counter[idx]++;
            currMax = Math.max(currMax, counter[idx]);
        }
    })

    counter = counter.map(val => (val > preMax)? val: preMax);

    return counter;
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N + M)

expand all Example tests

▶

example
example test

✔

0.068 s

expand all Correctness tests

▶

extreme_small
all max_counter operations

✔

0.068 s

▶

single
only one counter

✔

0.068 s

▶

small_random1
small random test, 6 max_counter operations

✔

0.068 s

▶

small_random2
small random test, 10 max_counter operations

✔

0.068 s

expand all Performance tests

▶

medium_random1
medium random test, 50 max_counter operations

✔

0.068 s

▶

medium_random2
medium random test, 500 max_counter operations

✔

0.072 s

▶

large_random1
large random test, 2120 max_counter operations

✔

0.108 s

▶

large_random2
large random test, 10000 max_counter operations

✔

0.128 s

▶

extreme_large
all max_counter operations

✔

0.176 s

0.168 s