Find first and last occurrences of an element in a sorted array. The question reads - Given an array of i.

Find first and last occurrences of an element in a sorted array The second line contains n numbers - the elements of the array.   Example 1: Input Dec 29, 2023 · Approaching this problem, you’ll use a binary search strategy to efficiently find the first and last occurrences of the target element within the sorted array. If target is not found in the array, return [-1, -1]. First and Last Position of Element in Sorted Array Intuition The task is to find the starting and ending position of a given target value in a sorted array. #sorting and searching #competitiveprogramming #coding #dsa Hey Guys in this video I have explained with code how we can solve the problem 'Find first and last positions of an element in a sorted BS-3. This is sorted in ascending order, we have to find the starting and ending position of a given target value. Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. In this approach, we iterate through the array using a for loop to find the first and last occurrence of the target element. If there are fewer than queries[i] occurrences of x, the answer should be -1 for that query. Next Permutation 32. Jul 23, 2025 · Given a sorted array arr [] with possibly some duplicates, the task is to find the first and last occurrences of an element x in the given array. Given a sorted array of n elements, possibly with duplicates, find the number of occurrences of the target element. May 11, 2022 · Given an array in a sorted way along with a target element, find its first and last index in an efficient way. This is a great way to improve your coding skills and analyze y In this problem, you must find the first and last occurrences of a target value in a sorted array. LeetCode Solutions in C++23, Java, Python, MySQL, and TypeScript. Contribute to MAZHARMIK/Interview_DS_Algo development by creating an account on GitHub. Given a sorted array arr containing n elements with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value. Given a sorted array with possibly duplicate elements. Is this already implemented in Julia? I did not find anything on the docs for findfirst. 3K May 1, 2020 · Given a sorted array A [] with possibly duplicate elements, write a program to find indexes of first and last occurrences of an element k in the given array. cpp. 2K subscribers Subscribe Jan 23, 2023 · This question has been asked in the interview of Facebook, Google, and Microsoft and is a Leetcode problem number 34. As the problem statement already mentions that the array is Sorted, we can implement it into our solution. Find First And Last Position Of Element In Sorted Array Problem Statement Given an array of integers sorted in ascending order, find the starting and ending position… Given a sorted array having N elements, find the indices of the first and last occurrences of an element X in the given array. Jul 23, 2025 · Given an array of integers, task is to find the starting and ending position of a given key. Apr 29, 2021 · April 2021 Leetcode ChallengeLeetcode - Find First and Last Position of Element in Sorted Array #34Difficulty: Medium Jul 23, 2025 · If the key element is not found in the array or the number of occurrences of the key element in the array is less than k, return -1. Output Format: Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If the target does not exist in the array, return [-1, -1]. Example 1: Sep 5, 2024 · Here, the target 6 is not found in the array, so the output is [-1,-1]. May 11, 2024 · Ace Leetcode’s 34 — Find First and Last position of element in sorted array challenge using binary search. Super Repository for Coding Interview Preperation. Using binary search algorithm to find the first occurrence, last occurrence and the count of an element in a sorted array with duplicate elements. Dec 21, 2022 · In my case, I am only interested in the indexes of the first and last True values in the array and therefore I'd rather not use np. When target is found, the algorithm should return the indices of its first and last appearance within the array. If the target is not found in the array, return [-1, -1]. Problem Note . For large datasets, this difference in performance can be significant. First, we find the index of the first occurrence (Lower Bound) of target and then the index of the first element greater than the target (Upper Bound). By leveraging binary search, you can find the first and last positions of the target element in O (log n) time, whereas a linear search would take O (n) time. If the element is not present in the array, report that as well. 'arr' may contain duplicate elements. Sep 6, 2024 · Find First and last position of element in sorted array. 7K subscribers Subscribe May 26, 2025 · The task is centralized around finding the starting and ending position of a specific value referred to as target within a sorted array nums. Return an integer array answer Aug 2, 2023 · I am solving a leetcode problem of finding the first and last occurrence of an element in an sorted array. Find First and Last Position of Element in Sorted Array - LeetCode Wiki Home Cracking the Coding Interview Focused Training Contest LeetCode Wiki doocs/leetcode Home LeetCode LeetCode Mar 20, 2025 · Using a Simple Loop This is the simplest and most direct approach. Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Your algorithm’s runtime complexity must be in the order of O (log n). I'd prefer not to convert my array into a list and use the index() method. First and Last Occurrences in Array | Count occurrences in Array take U forward 796K subscribers 8. Dec 28, 2021 · There is a interview question from AirBNB: You have a sorted array, and you want get the first index and the last index of the matching occurrence of an element by a function in python. Follow our clear and concise explanation to understand the approach and code for this problem. Valid Sudoku 37. Jan 24, 2024 · By employing binary search logic, it navigates through sorted arrays to pinpoint the first and last occurrences of a target value. Jul 16, 2022 · In this video, we will see another popular Binary Search Question "Find First and Last Position of Element in Sorted Array". If target is not found in the array, return [-1, -1] Example 1 : Jan 24, 2021 · In this video we will discuss problem - find first and last occurrence of element in sorted array LeetCode https://leetcode. 2K subscribers Subscribe BS-3. Examples: Inpu Apr 29, 2021 · Detailed explanation for Find First and Last Position of Element in Sorted Array leetcode 34. Store this index in the ans variable. The frequency of the target element is then calculated as the difference between these indices plus one. Binary Search Introduction | Real Life Example | Iterative | Recursive | Overflow Cases Given a sorted array arr containing n elements with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. Feb 19, 2022 · Find First and Last Occurrences of an Element in a Sorted Array – Linear Search The simplest approach is to traverse an array and find the indexes of first and last occurrences of x where x is a target number. For the input array [2, 5, 5, 5, 6, 6, 8, 9, 9, 9] with target 5, the output is (1, 3), indicating that 5 first appears at index 1 and last appears at index 3. The task is to find indexes of first and last occurrences of an element X in the given array. Given a sorted array of integers and a target integer, find the first occurrence of the target and return its index. Oct 9, 2023 · Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Write a code to find first and last position of a given number. The program implements two modified binary searches to find the first and last occurrences of a target number in a sorted array. Find First and Last Position of Element in Sorted Array 35. Steps for Implementation: Take the input for the sorted array and the target element. We will write two helper functions to achieve this Jan 9, 2021 · You have been given a sorted array/list 'arr' consisting of ‘n’ elements. You are also given an integer ‘k’. Binary Search to find the count (frequency) of an element in a sorted array This problem is a variation of the problem Find the First and Last Position of an Element in a Sorted Array. Since the array is sorted, we can leverage binary search to efficiently find these positions. Your task is to find the starting and ending positions of a given target value within this array. Approach The problem can be broken down into two main tasks: Finding the leftmost (first) position of the target. but even though I'm passing the ryt Master LeetCode Problem 34: Find the First and Last Position of an Element in a Sorted Array!Struggling to find the first and last occurrences of a target el Feb 9, 2023 · Now, since this blog is all about finding the first and last position of elements in a sorted array, have a look at a brief discussion on sorted arrays and we shall move further to solving the problem statement. Feb 2, 2016 · Binary search on an array which contains a sorted set of values, where values may occur more than once does not necessarily yield the first or last element. Jun 16, 2021 · 0 I am trying to solve the LeetCode problem Find First and Last Position of Element in Sorted Array: Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value. Jan 30, 2025 · By using binary search in a strategic way, we can efficiently determine the first and last occurrences of a target element in a sorted array. However, this only works if the array has unique values. Conclusion This problem involves locating all occurrences of a target element in a sorted array. Note: If the number x is not found in the array then return both the indices as -1. Note: If the number x is not found in the array just print '-1'. Sep 12, 2019 · LeetCode Find First and Last Position of Element in Sorted Array Solution Explained - Java Nick White 395K subscribers 2. In this video, we dive into the efficient method of using binary search to find the first and last occurrence of an element in a sorted You are gIven an array of integers that is sorted in an ascending order and a target value. FIND FIRST AND LAST POSITIONS OF AN ELEMENT IN A SORTED ARRAY: Given a sorted array with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Here is a solution for the Leetcode task "Find First and Last Position of Element in Sorted Array". Input: The first line contains a natural n (1 s ns105) – the quantity of elements of the array. Given an array of integers sorted in ascending order, the program should find the first and last occurrence of a given element. Longest Valid Parentheses 33. This can be done with linear search as Aug 3, 2022 · We have a sorted array with duplicate elements and we have to find the index of last duplicate element and print index of it and also print the duplicate element. com/problems/find-fi Sep 3, 2024 · Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Can you solve this real interview question? Find Occurrences of an Element in an Array - You are given an integer array nums, an integer array queries, and an integer x. First and Last Occurrences in Array | Count occurrences in Array BS-1. Or should I? Top 150 interview question seriesFind First and Last position of element in sorted arrayLeetcode problem number 34JAVA interview programming playlist: https: Aug 29, 2024 · In the above code, we first define two binary search functions, find_first_occurrence and find_last_occurrence, to find the indices of the first and last occurrences of the target element in the sorted array, respectively. Feb 23, 2025 · In this problem, we need to find the first and the last occurrence of a target element in a sorted array. The most efficient approach that we can take is using Binary Search. Today we are going to learn how to Find first and last positions or occurrences of an element in a sorted array in C++. Note: If the number x is not found in the array then return both the indices as -1. You are given an array of integers nums that is sorted in non-decreasing order (ascending order, allowing duplicates). Note: If the number X is not found in the array, return '-1' as an array. Example: Input: 'arr' = [0,1,1,5] , 'k' = 1 Output: 1 2 Mar 12, 2021 · Hello LeetCode enthusiasts 👋! Today we will be discussing a new problem which uses variation of binary search. This method significantly outperforms brute-force approaches, making it ideal for large datasets. Now, your task is to find the first and last occurrence of ‘k’ in 'arr'. Nov 28, 2019 · Given a sorted array with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. Sudoku Solver Question: C++ Given a sorted array arr containing n elements with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. Maintain two separate functions… Sep 23, 2023 · In this video, we are given, a sorted array arr containing n elements with possibly duplicate is to find indexes of first elements. First and last occurrence of an element Given a sorted array with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. Search Insert Position 36. 31. Jan 22, 2018 · Given a sorted array with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. Given a sorted array with possibly duplicated elements like [1,1,2,2,2,2,3], the following code with time complexity O (logn) finds the indexes of the first and last occurrences of an element in the given array. For this purpose first we will use linear search and then binary search Jan 29, 2025 · Given a sorted array arr of integers and a target value, you need to find the first and last position of the target in the array. Then this problem is a must-know! Problem: Given a sorted array with possible duplicate elements, find the first and last occurrence of a given number x. The difference between these two indices will give the total number of occurrences of the Nov 2, 2012 · Since the array that will be passed into the method will be sorted, I'm assuming that I can take advantage of using a Binary Search since this will be O (log n). Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. The second line contains 'n' space-separated integers denoting the array elements. 2. When found from either side, assign that index as its first and last position of First and Last Occurrences of x in sorted array where x is a target value Given a sorted array of integers (Sorted in ascending order). Get Discount on GeeksforGeeks courses (https://practice. Feb 16, 2024 · In this blog we’ll be using binary search to find the first and the last occurrences of the target element in the sorted array/list. The findFrequency method first finds the first and last occurrences of the target element in the sorted array using modified binary search. Since this element could be surrounded by by more matching elements, a second step is required, in order to find the first and last matching element. For each queries[i], you need to find the index of the queries[i]th occurrence of x in the nums array. Sep 18, 2025 · Given a sorted integer array, find the index of a given number's first or last occurrence. When the target is not found in the array, return [-1, -1]. Nov 13, 2023 · Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. U Feb 23, 2024 · A solution to LeetCode 34. 🎇 Description: You are given a Oct 12, 2014 · How to find first and last occurrences of a particular value in an array? Asked 11 years, 1 month ago Modified 11 years, 1 month ago Viewed 2k times Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Aug 10, 2023 · In this tutorial, we will learn how to find the number of occurrences for any given element in a sorted array using C++ program? Sep 3, 2022 · I am trying to solve my university question these is my assignment question: Question: Given a sorted array arr containing n elements with possibly duplicate elements, the task is to find indexes of Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Algorithm to find best insert position in sorted array. Find First and Last Position of Element in Sorted Array Leetcode 34 Solution | Searching and Sorting Oct 30, 2020 · Input Format: The first line contains the integer 'n', denoting the size of the sorted array. A better way to prepare for coding interviews. This array is characterized by its elements being sorted in non-decreasing order. In this problem, we need to find the first and the last occurrence of a target element in a sorted array. Additional Resources For further reading and practice problems, consider the following resources: LeetCode: Find First and Last Position of Element in Sorted Array GeeksforGeeks: Count number of occurrences (or frequency) in a sorted array Coursera: Algorithms Part I Day 16 of My GeeksforGeeks 30 Days Coding Challenge 😇 🚀 Today's Problem Statement: Find the first and last occurrences of an element in a sorted array. Description Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value. Since it is a sorted array I'm using binary search. Since the Binary Search will finish after the first "find" of a particular value. Binary search is used because the array is sorted, making it possible to efficiently narrow down the search space. The task is to find the first and last occurrences of an element x in the given array. Jul 23, 2025 · Binary search can be used to find the number of occurrences of an element in a sorted array by finding the first and last occurrences of the element and subtracting 1. *"Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Discover efficient solutions to find the first and last positions of an element in a sorted array. You have to find the first and the last occurrences of a given number k in an array. My first Oct 9, 2023 · In this article, we tackled problem 34, “Find First and Last Position of Element in Sorted Array,” by strategically employing binary search to determine the starting and ending positions of a Jan 3, 2016 · Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. It yields the first matching element it finds. Loop through the array to check Dec 9, 2016 · Given a sorted array of n elements, possibly with duplicates, find the number of occurrences of the target element. The third line contains the value 'x', whose first and last position of occurrence you need to find. Jun 25, 2025 · LeetCode Problem:- 34 Find First and Last Position of Element in Sorted Array Cloudcredits Technologies 11. Search in Rotated Sorted Array 34. But I want to exploit the fact that A is already sorted (binary search). Given a sorted array A [] with possibly duplicate elements, write a program to find indexes of first and last occurrences of an element k in the given array. Aug 20, 2022 · In this video, we will about the implementation of Binary Search algorithm and will solve the "First and last occurrences of X" problem available on GeeksFor Sep 12, 2025 · The idea is to find the index of the first and last occurrence of every distinct number in the array and update the difference between two indices in a map. Your algorithm's runtime complexity must be in the order of O (log n). Problem Name : Find F Oct 3, 2025 · Since the array is already sorted, we can use binary search to find the occurrences of a given target. Note : 1. Sep 30, 2024 · Q: What is the time complexity of finding the first and last positions of an element in a sorted array using binary search? A: The time complexity is O (log n), where n is the length of the array. First and Last Position of Element in Sorted Array - Binary Search - Leetcode 34 BS-3. Initialize two variables, first and last, to store the first and last occurrences. Oct 3, 2023 · With this article by Scaler Topics we will learn How to Find First and Last Position of Element in Sorted Array along with their examples and explanations. Note: If the element is not present in the array return {-1,-1} as pair. Jan 31, 2025 · In this video, we tackle an important Data Structures and Algorithms (DSA) problem: Finding the First and Last Occurrences of an Element in a Sorted Array. Explore code examples in C++, Java, Python, and JavaScript. We use binary search to lower the time complexity of course Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. geeksfor Jan 6, 2024 · Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. The goal is to efficiently find the first and last occurrence of the… Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. Mar 21, 2024 · We will find the first and last position of element in a sorted array using binary search, with implementation in C++, Java, and Python. Finding the rightmost (last) position of the target. Aug 21, 2020 · First and last occurrence of an element: Given a sorted array with possibly duplicate elements, the task is to find indexes of first and last occurrences of an element x in the given array. The goal is to design an algorithm with O (log n) time complexity. The question reads - Given an array of i Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. You must write an algorithm with O (log n) runtime complexity. Find the index of first and last occurrence of the element in a fastest way possible. Dec 17, 2023 · Since it is sorted, we can traverse through it and find occurrence of the element from left side and right side. Oct 3, 2025 · Learn how to find the first and last positions of an element in a sorted array using both brute force and optimized binary search approaches with code examples. Dec 29, 2023 · 🚀 Exploring Efficient Searching: Finding First and Last Position of Element in Sorted Array Hey LinkedIn community! 👋 Today, let's dive into an interesting algorithmic problem and explore a Jan 2, 2023 · Join Avneet Kaur as she solves the school practice problem: First and last occurrences of x . Feb 23, 2025 · Finding the First and Last Position of an Element in a Sorted Array. Given a sorted array arr with possibly some duplicates, the task is to find the first and last occurrences of an element x in the given array. So, to get the indices of val in a sorted array, instead of performing sort operation, we can simply count the elements less than val. Otherwise, calculate the index of the kth occurrence of the key element by adding k-1 to lb. argwhere in order to avoid going through the entire array unnecessarily. where or np. Question: Task: You are given a sorted array of n integer elements. Input: The first line of input contains an integer T denoting the no of test cases. You must write an algorithm with O(log n) runtime complexity. If ‘k’ is not present in the array, then the first and the last occurrence will be -1. Jul 18, 2017 · I have a sorted array of numbers: A = [1, 4, 10, 15, 18] I want to determine the first index where a value, v, occurs in this array (or 0 if it does not occur), like findfirst(A, v). 046. Return -1 if the target is not in the array. In the following solution, we will use STL’s std::upper_bound and std::lower_bound to find the first and last occurrence of each element using binary search algorithm. Jul 23, 2025 · In an array which is sorted in increasing order all the elements before val are less than val. 1K LeetCode solutions in any programming language34. This question will clear your concept of Binary Search Oct 9, 2023 · Find First and Last Position of Element in Sorted Array | Leetcode 34 Ayushi Sharma 52. Given an array of integer nums sorted in non-decreasing order, find the starting and ending position of a given target value. tueka cjyeyl oajzyt imerf towj wxgk edmw ippe bqxk qabnvtjy zpgay bjpsztl fdlbx txav irawlju