X

DAYS

:

HOUR

:

MINS

:

SEC

Copied to Clipboard
Sorted subsequence of size 3
Easy Accuracy: 45.69% Submissions: 33761 Points: 2

Given an array A of N integers, find any 3 elements in it such that A[i] < A[j] < A[k] and i < j < k.

Example 1:

Input:
N = 5
A[] = {1,2,1,1,3}
Output: 1
Explanation: a sub-sequence 1 2 3 exist.


Example 2:

Input:
N = 3
A[] = {1,1,3}
Output: 0
Explanation: no such sub-sequence exist.

Your task is to complete the function find3Numbers which finds any 3 elements in it such that A[i] < A[j] < A[k] and i < j < k. You need to return them as a vector/ArrayList/array (depending on the language cpp/Java/Python), if no such element is present then return the empty vector of size 0.

Note: The output will be 1 if the sub-sequence returned by the function is present in array A else 0. If the sub-sequence returned by the function is not in the format as mentioned then the output will be -1.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(N)

Constraints:
1 <= N <= 105
1 <= A[i] <= 106, for each valid i

Note: The Input/Output format and Examples given are used for the system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from stdin/console. The task is to complete the function specified, and not to write the full code.