Last index of element

Easy

0/40

81 upvotes

Asked in company

Problem statement

Take an array with N elements with possibly duplicate elements as the input. The task is to find the index of the last occurrences of the element x in the array and, if it is not present, return -1.

Detailed explanation ( Input/output format, Notes, Images )

Input Format:

The first line contains an integer N representing the size of the array.

The next line contains N space-separated integers representing the elements of the array.

The last line contains an integer 'x' whose index has to be found.

Output Format:

The only line of the output prints the Index or -1.

Constraints:

1 <= N <= 10^3
1 <= arr[i] <= 10^9
1 <= x < N

Sample Input 1 :

8
7 5 2 11 2 43 1 1
2

Sample Output 1 :

Explanation of Sample Input 1:

2 is present twice in the input array and the last time it appears is at index 4.

Sample Input 2 :

8
7 5 2 11 2 43 1 1
10

Sample Output 2 :

-1

Explanation of Sample Input 2:

10 is not present in the array so the output is -1.

Approaches (1)

Approach 1

Brute Force approach

We create a variable last with value -1 to store the answer.
We iterate the array backwards and update the value of last if an occurrence of x is found. We break out of this loop.
Finally, print the value of last.

Time Complexity

Space Complexity

(100% EXP penalty)

Last index of element

Console