Test results - Codility

Tasks Details

easy

1. TapeEquilibrium

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

Task Score

83%

Correctness

100%

Performance

66%

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:

class Solution { public int solution(int[] 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 Java 8

Time spent on task 6 minutes

Notes

not defined yet

Task timeline

Code: 11:01:53 UTC, java, 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 28

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=Math.abs(sum-diffS);
            diff=Math.abs(diff-diffS);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

Analysis

expand all Example tests

▶

example
example test

✔

1.315 s

expand all User tests

▶

test_data1

✔

1.305 s

OK
function result: 27

Code: 11:02:27 UTC, java, 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 28

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+Math.abs(A[i]);
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=Math.abs(sum-diffS);
            diff=Math.abs(diff-diffS);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

Analysis

expand all Example tests

▶

example
example test

✔

1.319 s

expand all User tests

▶

test_data1

✔

1.316 s

OK
function result: 47

Code: 11:02:48 UTC, java, 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 28

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=Math.abs(sum-diffS);
            diff=Math.abs(diff-diffS);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

Analysis

expand all Example tests

▶

example
example test

✔

1.302 s

expand all User tests

▶

test_data1

✔

1.293 s

OK
function result: 27

Code: 11:03:26 UTC, java, 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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=Math.abs(sum-diffS);
            diff=Math.abs(diff-diffS);
            System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

Analysis

expand all Example tests

▶

example
example test

✔

1.325 s

stdout:

expand all User tests

▶

test_data1

✔

1.326 s

OK
function result: 27

stdout:

Code: 11:04:38 UTC, java, 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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=sum-diffS;
            diff=Math.abs(diff-diffS);
            System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

Analysis

expand all Example tests

▶

example
example test

✔

1.309 s

stdout:

expand all User tests

▶

test_data1

✔

1.307 s

OK
function result: 3

stdout:

Code: 11:04:57 UTC, java, 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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=sum-diffS;
            diff=Math.abs(diff-diffS);
           // System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

Analysis

expand all Example tests

▶

example
example test

✔

1.325 s

expand all User tests

▶

test_data1

✔

1.079 s

OK
function result: 3

Code: 11:05:17 UTC, java, 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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=sum-diffS;
            diff=Math.abs(diff-diffS);
           // System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

User test case 2:

[-1000, 1000]

Analysis

expand all Example tests

▶

example
example test

✔

1.339 s

expand all User tests

▶

test_data1

✔

1.352 s

OK
function result: 3

▶

test_data2

✔

1.338 s

OK
function result: 2000

Code: 11:05:47 UTC, java, 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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=sum-diffS;
            diff=Math.abs(diff-diffS);
           // System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

User test case 2:

[-1000, 1000]

User test case 3:

[-1, -1, -1, -1, -1, -1, -1, -1]

Analysis

expand all Example tests

▶

example
example test

✔

1.341 s

expand all User tests

▶

test_data1

✔

1.347 s

OK
function result: 3

▶

test_data2

✔

1.193 s

OK
function result: 2000

▶

test_data3

✔

1.061 s

OK
function result: 2

Code: 11:06:15 UTC, java, 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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=sum-diffS;
            diff=Math.abs(diff-diffS);
           // System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

User test case 1:

[-10, -5, -3, -4, -5]

User test case 2:

[-1000, 1000]

User test case 3:

[-1, -1, -1, -1, -1, -1, -1, -1]

Analysis

expand all Example tests

▶

example
example test

✔

1.315 s

expand all User tests

▶

test_data1

✔

1.290 s

OK
function result: 3

▶

test_data2

✔

1.291 s

OK
function result: 2000

▶

test_data3

✔

1.205 s

OK
function result: 2

Code: 11:06:27 UTC, java, final, score: 83

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 28 29

// 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
        int len=A.length;
        int sum=0;
        for(int i=0;i<len;i++){
            sum=sum+A[i];
        }
        
        int diff=0;
        int retValue=0;
        int diffS=0;
        for(int i=0;i<len-1;i++){
            diffS=diffS+A[i];
            diff=sum-diffS;
            diff=Math.abs(diff-diffS);
           // System.out.println(diff);
            if(retValue==0) retValue=diff;
            if(retValue>diff) retValue=diff;
        }
        return retValue;
    }
}

Analysis summary

The following issues have been detected: wrong answers.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example
example test

✔

1.330 s

expand all Correctness tests

▶

double
two elements

✔

1.335 s

1.327 s

▶

simple_positive
simple test with positive numbers, length = 5

✔

1.333 s

▶

simple_negative
simple test with negative numbers, length = 5

✔

1.325 s

▶

small_random
random small, length = 100

✔

1.331 s

▶

small_range
range sequence, length = ~1,000

✔

1.327 s

▶

small
small elements

✔

1.333 s

expand all Performance tests

▶

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

✔

1.360 s

▶

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

✔

1.344 s

▶

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

✘

WRONG ANSWER
got 2 expected 0

1.506 s

WRONG ANSWER, got 2 expected 0

1.486 s

▶

large_random
random large, length = ~100,000

✔

1.536 s

1.551 s

▶

large_sequence
large sequence, length = ~100,000

✔

1.417 s

▶

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

✘

WRONG ANSWER
got 2000 expected 0

1.572 s

WRONG ANSWER, got 2000 expected 0

1.562 s

WRONG ANSWER, got 2000 expected 0

1.509 s