PHP Program for Range Queries for Frequencies of Array Elements Last Updated : 22 Jul, 2024 Comments Improve Suggest changes Like Article Like Report Given an array of n non-negative integers. The task is to find the frequency of a particular element in the arbitrary range of array[]. The range is given as positions (not 0 based indexes) in array. There can be multiple queries of given type. Examples: Input : arr[] = {2, 8, 6, 9, 8, 6, 8, 2, 11}; left = 2, right = 8, element = 8 left = 2, right = 5, element = 6 Output : 3 1The element 8 appears 3 times in arr[left-1..right-1]The element 6 appears 1 time in arr[left-1..right-1]Naive ApproachThis approach is to traverse from left to right and update the count variable whenever we find the element. Below is the code of Naive approach: PHP <?php // PHP program to find total count of // an element in a range // Returns count of element in // arr[left-1..right-1] function findFrequency(&$arr, $n, $left, $right, $element) { $count = 0; for ($i = $left - 1; $i <= $right; ++$i) { if ($arr[$i] == $element) { ++$count; } } return $count; } // Driver Code $arr = [2, 8, 6, 9, 8, 6, 8, 2, 11]; $n = sizeof($arr); // Print frequency of 2 from position 1 to 6 echo "Frequency of 2 from 1 to 6 = " . findFrequency($arr, $n, 1, 6, 2) . ""; // Print frequency of 8 from position 4 to 9 echo "\nFrequency of 8 from 4 to 9 = " . findFrequency($arr, $n, 4, 9, 8); ?> OutputFrequency of 2 from 1 to 6 = 1 Frequency of 8 from 4 to 9 = 2Time complexity of this approach is O(right - left + 1) or O(n) Auxiliary space: O(1) Please refer complete article on Range Queries for Frequencies of array elements for more details! Comment More infoAdvertise with us Next Article PHP Program for Range Queries for Frequencies of Array Elements kartik Follow Improve Article Tags : PHP array-range-queries Similar Reads Javascript Program for Range Queries for Frequencies of array elements Given an array of n non-negative integers. The task is to find frequency of a particular element in the arbitrary range of array[]. The range is given as positions (not 0 based indexes) in array. There can be multiple queries of given type. Examples: Input : arr[] = {2, 8, 6, 9, 8, 6, 8, 2, 11}; lef 2 min read Range Queries for Frequencies of array elements Given an array of n non-negative integers. The task is to find frequency of a particular element in the arbitrary range of array[]. The range is given as positions (not 0 based indexes) in array. There can be multiple queries of given type. 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