Find first and last position of element in sorted array.
Given a sorted array which contains duplicate elements. Write a code to find first and last position of a number in a sorted array.
OR
Find first and last occurrences of x in sorted array where x is a target value.
If a number is not found return -1.
For example –
Example 1 –
Input : {1, 4, 7, 8, 8, 11, 11, 11, 11, 12, 13, 13} , target = 11
Output: {5, 8}
The first index of 11 is 5 and last index is 8.
Example 2 –
Input: {1, 6, 7, 7, 8, 8, 9, 9}, target = 5
Output: {-1, -1}
The target value is not found.
NOTE – We have to solve this problem in O(logn) time complexity.
Write a PHP code to find second largest number in array. Given an unsorted array, we have to write a PHP program to find the second largest number in an array.
Apart from solving this problem. We have to focus on time complexity. As the time complexity of an algorithm is very important in terms of how efficient your algorithm is.