Test results - Codility

Tasks Details

easy

1. Triangle

Determine whether a triangle can be built from a given set of edges.

Task Score

100%

Correctness

100%

Performance

100%

An array A consisting of N integers is given. A triplet (P, Q, R) is triangular if 0 ≤ P < Q < R < N and:

A[P] + A[Q] > A[R],

A[Q] + A[R] > A[P],

A[R] + A[P] > A[Q].

For example, consider array A such that:

A[0] = 10 A[1] = 2 A[2] = 5 A[3] = 1 A[4] = 8 A[5] = 20

Triplet (0, 2, 4) is triangular.

Write a function:

class Solution { public int solution(int[] A); }

that, given an array A consisting of N integers, returns 1 if there exists a triangular triplet for this array and returns 0 otherwise.

For example, given array A such that:

A[0] = 10 A[1] = 2 A[2] = 5 A[3] = 1 A[4] = 8 A[5] = 20

the function should return 1, as explained above. Given array A such that:

A[0] = 10 A[1] = 50 A[2] = 5 A[3] = 1

the function should return 0.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [0..100,000];

each element of array A is an integer within the range [−2,147,483,648..2,147,483,647].

Solution

Programming language used Java 8

Time spent on task 1 minutes

Notes

not defined yet

Code: 08:33:00 UTC, java, autosave

show code in pop-up

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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: 08:33:03 UTC, java, verify, result: Failed

show code in pop-up

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// you can also use imports, for example:
// import java.math.*;
 
import java.util.Arrays;
 
class Solution {
    /**
     * Check whether there is a triangular
     * @param A         The array for length of lines
     * @return          0: no triangular found
     *                  1: triangular is found
     */
    public int solution(int[] A) {
        // Handle with the special cases
        if(null == A || A.length < 3) return 0;
 
        // Sort the input, and then try to find the triangular
        Arrays.sort(A);
        for(int i = 0; i < A.length-2; i++) {
            // Beware of overflow
            if (A[i] >= 0 && A[i] > A[i+2] - A[i+1]) {
                return 1;
            }
            /*
             * We already know A[i+1] <= A[i+2]. If A[i] < 0,
             * A[i] + A[i+1] < A[i+2]
             */
        }
        return 0;
    }
}

Analysis

Compile error

Solution.java:1: error: class, interface, or enum expected
1
^
Solution.java:2: error: class, interface, or enum expected
2
^
Solution.java:3: error: class, interface, or enum expected
3
^
Solution.java:4: error: class, interface, or enum expected
4
^
Solution.java:5: error: class, interface, or enum expected
5
^
Solution.java:6: error: class, interface, or enum expected
6
^
Solution.java:7: error: class, interface, or enum expected
7
^
Solution.java:8: error: class, interface, or enum expected
8
^
Solution.java:9: error: class, interface, or enum expected
9
^
Solution.java:10: error: class, interface, or enum expected
10
^
Solution.java:11: error: class, interface, or enum expected
11
^
Solution.java:12: error: class, interface, or enum expected
12
^
Solution.java:13: error: class, interface, or enum expected
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^
Solution.java:14: error: class, interface, or enum expected
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^
Solution.java:15: error: class, interface, or enum expected
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^
Solution.java:16: error: class, interface, or enum expected
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^
Solution.java:17: error: class, interface, or enum expected
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^
Solution.java:18: error: class, interface, or enum expected
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^
Solution.java:19: error: class, interface, or enum expected
19
^
Solution.java:20: error: class, interface, or enum expected
20
^
Solution.java:21: error: class, interface, or enum expected
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^
Solution.java:22: error: class, interface, or enum expected
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^
Solution.java:23: error: class, interface, or enum expected
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^
Solution.java:24: error: class, interface, or enum expected
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^
Solution.java:25: error: class, interface, or enum expected
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^
Solution.java:26: error: class, interface, or enum expected
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^
Solution.java:27: error: class, interface, or enum expected
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^
Solution.java:28: error: class, interface, or enum expected
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^
Solution.java:29: error: class, interface, or enum expected
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^
Solution.java:30: error: class, interface, or enum expected
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^
Solution.java:31: error: class, interface, or enum expected
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^
31 errors

Code: 08:33:26 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 30 31 32


// you can also use imports, for example:
// import java.math.*;
 
import java.util.Arrays;
 
class Solution {
    /**
     * Check whether there is a triangular
     * @param A         The array for length of lines
     * @return          0: no triangular found
     *                  1: triangular is found
     */
    public int solution(int[] A) {
        // Handle with the special cases
        if(null == A || A.length < 3) return 0;
 
        // Sort the input, and then try to find the triangular
        Arrays.sort(A);
        for(int i = 0; i < A.length-2; i++) {
            // Beware of overflow
            if (A[i] >= 0 && A[i] > A[i+2] - A[i+1]) {
                return 1;
            }
            /*
             * We already know A[i+1] <= A[i+2]. If A[i] < 0,
             * A[i] + A[i+1] < A[i+2]
             */
        }
        return 0;
    }
}

Analysis

expand all Example tests

▶

example
example, positive answer, length=6

✔

0.008 s

▶

example1
example, answer is zero, length=4

✔

0.004 s

Code: 08:33:30 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 30 31 32


// you can also use imports, for example:
// import java.math.*;
 
import java.util.Arrays;
 
class Solution {
    /**
     * Check whether there is a triangular
     * @param A         The array for length of lines
     * @return          0: no triangular found
     *                  1: triangular is found
     */
    public int solution(int[] A) {
        // Handle with the special cases
        if(null == A || A.length < 3) return 0;
 
        // Sort the input, and then try to find the triangular
        Arrays.sort(A);
        for(int i = 0; i < A.length-2; i++) {
            // Beware of overflow
            if (A[i] >= 0 && A[i] > A[i+2] - A[i+1]) {
                return 1;
            }
            /*
             * We already know A[i+1] <= A[i+2]. If A[i] < 0,
             * A[i] + A[i+1] < A[i+2]
             */
        }
        return 0;
    }
}

Analysis

expand all Example tests

▶

example
example, positive answer, length=6

✔

0.004 s

▶

example1
example, answer is zero, length=4

✔

0.008 s

Code: 08:33:35 UTC, java, 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 28 29 30 31 32


// you can also use imports, for example:
// import java.math.*;
 
import java.util.Arrays;
 
class Solution {
    /**
     * Check whether there is a triangular
     * @param A         The array for length of lines
     * @return          0: no triangular found
     *                  1: triangular is found
     */
    public int solution(int[] A) {
        // Handle with the special cases
        if(null == A || A.length < 3) return 0;
 
        // Sort the input, and then try to find the triangular
        Arrays.sort(A);
        for(int i = 0; i < A.length-2; i++) {
            // Beware of overflow
            if (A[i] >= 0 && A[i] > A[i+2] - A[i+1]) {
                return 1;
            }
            /*
             * We already know A[i+1] <= A[i+2]. If A[i] < 0,
             * A[i] + A[i+1] < A[i+2]
             */
        }
        return 0;
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N*log(N))

expand all Example tests

▶

example
example, positive answer, length=6

✔

0.004 s

▶

example1
example, answer is zero, length=4

✔

0.004 s

expand all Correctness tests

▶

extreme_empty
empty sequence

✔

0.004 s

0.008 s

0.004 s

▶

extreme_single
1-element sequence

✔

0.008 s

0.004 s

0.008 s

0.004 s

▶

extreme_two_elems
2-element sequence

✔

0.004 s

0.008 s

▶

extreme_negative1
three equal negative numbers

✔

0.004 s

▶

extreme_arith_overflow1
overflow test, 3 MAXINTs

✔

0.004 s

▶

extreme_arith_overflow2
overflow test, 10 and 2 MININTs

✔

0.004 s

▶

extreme_arith_overflow3
overflow test, 0 and 2 MAXINTs

✔

0.008 s

0.004 s

▶

medium1
chaotic sequence of values from [0..100K], length=30

✔

0.008 s

0.004 s

▶

medium2
chaotic sequence of values from [0..1K], length=50

✔

0.004 s

▶

medium3
chaotic sequence of values from [0..1K], length=100

✔

0.004 s

expand all Performance tests

▶

large1
chaotic sequence with values from [0..100K], length=10K

✔

0.032 s

0.004 s

0.008 s

0.004 s

▶

large2
1 followed by an ascending sequence of ~50K elements from [0..100K], length=~50K

✔

0.124 s

0.008 s

0.004 s

▶

large_random
chaotic sequence of values from [0..1M], length=100K

✔

0.296 s

0.004 s

0.008 s

▶

large_negative
chaotic sequence of negative values from [-1M..-1], length=100K

✔

0.292 s

0.004 s

0.008 s

0.004 s

▶

large_negative2
chaotic sequence of negative values from [-10..-1], length=100K

✔

0.168 s

0.004 s

0.008 s

0.004 s

▶

large_negative3
sequence of -1 value, length=100K

✔

0.160 s

0.004 s