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Tracks

Given an array of n elements that contains elements from 0 to n-1, with any of these numbers appearing any number of times. Find these repeating numbers in O(n) and using only constant memory space.Example:Input : n = 7 and array[] = {1, 2, 3, 6, 3, 6, 1} Output: 1, 3, 6Explanation: The numbers 1 , 3 and 6 appears more than once in the array.Find duplicates in O(n) time and O(1) extra space: <a href="https://www.geeksforgeeks.org/find-duplicates-in-on-time-and-constant-extra-space/">https://www.geeksforgeeks.org/find-duplicates-in-on-time-and-constant-extra-space/</a>

Find duplicates in O(n) time and O(1) extra space

Print the elements of an array in the decreasing frequency if 2 numbers have same frequency then print the one which came first.Examples: &nbsp;Input: &nbsp;arr[] = {2, 5, 2, 8, 5, 6, 8, 8} Output: arr[] = {8, 8, 8, 2, 2, 5, 5, 6}Input: arr[] = {2, 5, 2, 6, -1, 9999999, 5, 8, 8, 8} Output: arr[] = {8, 8, 8, 2, 2, 5, 5, 6, -1, 9999999}Sort elements by frequency _ Set 1: <a href="https://www.geeksforgeeks.org/sort-elements-by-frequency/">https://www.geeksforgeeks.org/sort-elements-by-frequency/</a>

Sort elements by frequency

Create a data structure twoStacks that represents two stacks. Implementation of twoStacks should use only one array, i.e., both stacks should use the same array for storing elements. Following functions must be supported by twoStacks. push1(int x) –&gt; pushes x to first stack&nbsp; push2(int x) –&gt; pushes x to second stack pop1() –&gt; pops an element from first stack and return the popped element&nbsp; pop2() –&gt; pops an element from second stack and return the popped element Implementation of twoStack should be space efficient.Implement two stacks in an array: <a href="https://www.geeksforgeeks.org/implement-two-stacks-in-an-array/">https://www.geeksforgeeks.org/implement-two-stacks-in-an-array/</a>

Implement two stacks in an array

Given an array of integers, find all combination of four elements in the array whose sum is equal to a given value X.&nbsp; For example, if the given array is {10, 2, 3, 4, 5, 9, 7, 8} and X = 23, then your function should print “3 5 7 8” (3 + 5 + 7 + 8 = 23). A Naive Solution is to generate all possible quadruples and compare the sum of every quadruple with X. The following code implements this simple method using four nested loops&nbsp; &nbsp;Find four elements that sum to a given value _ Set 1 (n^3 solution): <a href="https://www.geeksforgeeks.org/find-four-numbers-with-sum-equal-to-given-sum/">https://www.geeksforgeeks.org/find-four-numbers-with-sum-equal-to-given-sum/</a>

Find four elements that sum to a given value | Set 1 (n^3 solution)

Given an array of integers, find the first repeating element in it. We need to find the element that occurs more than once and whose index of first occurrence is smallest.Examples:Input: &nbsp;arr[] = {10, 5, 3, 4, 3, 5, 6} Output: 5 [5 is the first element that repeats]Input: &nbsp;arr[] = {6, 10, 5, 4, 9, 120, 4, 6, 10} Output: 6 [6 is the first element that repeats]Find the first repeating element in an array of integers : <a href="https://www.geeksforgeeks.org/find-first-repeating-element-array-integers/">https://www.geeksforgeeks.org/find-first-repeating-element-array-integers/</a>

Find the first repeating element in an array of integers

Given an array of even size, task is to find minimum value that can be added to an element so that array become balanced. An array is balanced if the sum of the left half of the array elements is equal to the sum of right half. Suppose, we have an array 1 3 1 2 4 3. The Sum of first three elements is 1 + 3 + 1 = 5 and sum of last three elements is 2 + 4 + 3 = 9&nbsp; So this is unbalanced, to make it balanced the minimum number we can add is 4 to any element in first half. Examples :&nbsp; &nbsp;Input : 1 2 1 2 1 3 Output : 2 Sum of first 3 elements is 1 + 2 + 1 = 4,&nbsp; sum of last three elements is 2 + 1 + 3 = 6 To make the array balanced you can add 2. Find the minimum value to be added so that array becomes balanced: <a href="https://www.geeksforgeeks.org/find-the-minimum-value-to-be-added-so-that-array-becomes-balanced/">https://www.geeksforgeeks.org/find-the-minimum-value-to-be-added-so-that-array-becomes-balanced/</a>

Find the minimum value to be added so that array becomes balanced

To find the smallest positive number missing from an unsorted array, various approaches can be applied. The naive method sorts the array, while more efficient solutions use techniques like cycle sort or marking indices. Another approach involves negating array elements or using a visited array to track which numbers are present. These solutions have different time and space complexities, but all aim to find the first missing positive number. The cycle sort approach optimizes the space complexity to O(1) while maintaining O(n) time complexity. For more details, check out the full article: <a href="https://www.geeksforgeeks.org/find-the-smallest-positive-number-missing-from-an-unsorted-array/">Find Smallest Missing Positive Number</a>.

First Missing Positive

To find the maximum sum of a non-empty subarray in a circular array, you can use Kadane’s algorithm to calculate the maximum subarray sum for non-circular arrays. The circular subarray sum can be derived by subtracting the minimum subarray sum from the total array sum. This approach efficiently handles both circular and non-circular cases in linear time. The maximum sum is the larger of the normal subarray sum and the circular sum. Special cases where all elements are negative are handled by returning the normal maximum subarray sum. For more details, check out the full article: <a href="https://www.geeksforgeeks.org/maximum-contiguous-circular-sum/">Maximum Circular Subarray Sum</a>.

Maximum Sum Subarray in Circular

To find the maximum product of any subarray in Python, we can use an approach that tracks the maximum and minimum product at each index. This is done by considering both the current element and the product of the current element with the previous maximum and minimum. This ensures that the maximum product is updated at each step. The algorithm runs in linear time, making it efficient for large arrays. It avoids using nested loops and instead leverages simple comparisons to handle negative numbers and zeros. For more details, check out the full article: <a href="https://www.geeksforgeeks.org/maximum-product-subarray/">Maximum Product Subarray</a>.

Maximum Product Subarray

In this tutorial, learn how to find all elements in an array that occur more than [N/3] times. Discover the efficient algorithm to solve this problem without using extra space, by utilizing the Boyer-Moore Voting Algorithm.&nbsp; For more details, check out the full article: <a href="https://www.geeksforgeeks.org/find-all-array-elements-occurring-more-than-%E2%8C%8An-3%E2%8C%8B-times/">Majority Element II – Elements Occurring More Than ⌊N/3⌋ Times</a>.

Majority Element II

In this tutorial, learn how to minimize the maximum difference between the heights of towers by performing operations on the heights. Discover an efficient approach using sorting and greedy algorithms to minimize the difference while optimizing for time complexity.&nbsp; For more details, check out the full article: <a href="https://www.geeksforgeeks.org/minimize-the-maximum-difference-between-the-heights/">Minimize the Maximum Difference Between the Heights</a>.

Minimize the maximum difference between the heights

In this tutorial, learn how to reverse an array using different methods. Explore efficient algorithms, from using a simple loop to utilizing built-in functions, and understand their time and space complexities. Gain a deeper understanding of how array reversal works in programming.&nbsp; For more details, check out the full article: <a href="https://www.geeksforgeeks.org/program-to-reverse-an-array/">Array Reverse – Complete Tutorial</a>.

Array Reverse

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