First of all, here is the problem description:
A non-empty zero-indexed array A consisting of N integers is given.
A permutation is a sequence containing each element from 1 to N once, and only once.
For example, array A such that:
A[0] = 4
A[1] = 1
A[2] = 3
A[3] = 2
is a permutation, but array A such that:
A[0] = 4
A[1] = 1
A[2] = 3
is not a permutation.
The goal is to check whether array A is a permutation.
Write a function:
class Solution { public int solution(int[] A); }
that, given a zero-indexed array A, returns 1 if array A is a permutation and 0 if it is not.
For example, given array A such that:
A[0] = 4
A[1] = 1
A[2] = 3
A[3] = 2
the function should return 1.
Given array A such that:
A[0] = 4
A[1] = 1
A[2] = 3
the function should return 0.
Assume that:
N is an integer within the range [1..100,000];
each element of array A is an integer within the range [1..1,000,000,000].
Complexity:
expected worst-case time complexity is O(N);
expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).
Here is my solution to the problem:
But evertime I run it, I am gettign an error:
Running solution...
Compilation successful
Example test : example1 - OK
example2 - RUNTIME ERROR (tested program terminated unexpectedly)
Output:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
at Solution.solution(Solution.java:12)
at wrapper.run(wrapper.java:27)
at wrapper.main(wrapper.java:20)
Detected some errors.
Here is my sample
test data:
[4, 1, 3, 2]
I'm certain that it should not give any runtime errors. But why? Is this a bug?