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array sorting Pattern

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database42 problemstune18/23/1 difficulty mixcategory6 linked topics

Pattern brief

Recognize first

Checks if you sort intervals before merging, as failing to sort leads to incorrect merges.

Solve rhythm

State the active state and invariant first, explain how each update preserves them, then pressure-test with counterexamples.

Most common miss

Failing to sort intervals first, causing incorrect overlap detection.

Recognition signals

  • Checks if you sort intervals before merging, as failing to sort leads to incorrect merges.
  • Looks for a clean in-place or linear pass after sorting, showing understanding of array traversal and comparison.
  • Expect discussion on linear time sorting alternatives like bucket sort or radix sort.

Solve flow

  1. 1. Define the active state/window.
  2. 2. Update state while preserving invariants.
  3. 3. Validate with edge-heavy examples.

Common misses

  • Failing to sort intervals first, causing incorrect overlap detection.
  • Sorting the array normally violates the linear time constraint and may be penalized.
  • Miscounting papers with exactly h citations or assuming strict greater-than.

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array sorting pattern bank

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Showing 24 / 42 problems

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56

Merge Intervals

Merge Intervals requires sorting an array of interval pairs and combining overlaps efficiently using sequential comparis…

Medium
164

Maximum Gap

Find the largest difference between successive elements in a sorted array efficiently using linear time techniques and b…

Medium
274

H-Index

Determine a researcher's h-index by analyzing citations using array sorting and counting techniques efficiently and accu…

Medium
414

Third Maximum Number

Find the third distinct maximum number in an array using array traversal and sorting techniques, handling duplicates car…

Easy
506

Relative Ranks

Solve Relative Ranks by sorting scores with original indices, then writing medal labels or numeric places back in answer…

Easy
747

Largest Number At Least Twice of Others

Determine if the largest number in the array is at least twice as large as every other element, and return its index or …

Easy
1051

Height Checker

Determine how many students are out of place in a line by comparing their heights to the sorted expected order efficient…

Easy
1094

Car Pooling

Determine if a car can handle multiple trips without exceeding its capacity using array sorting and event simulation tec…

Medium
1200

Minimum Absolute Difference

Find all pairs with the minimum absolute difference between two elements in an array, and return them in ascending order…

Easy
1288

Remove Covered Intervals

Remove all intervals fully covered by another using sorting and linear traversal, counting only distinct remaining inter…

Medium
1329

Sort the Matrix Diagonally

Sort each diagonal of a matrix in ascending order, applying sorting and matrix traversal techniques.

Medium
1333

Filter Restaurants by Vegan-Friendly, Price and Distance

Filter restaurants by vegan-friendly status, price, and distance, and sort them by rating and ID.

Medium
1424

Diagonal Traverse II

Traverse a jagged 2D array diagonally by grouping elements with equal row and column sums efficiently using sorting and …

Medium
1464

Maximum Product of Two Elements in an Array

Find the maximum product of two elements in an array by carefully selecting indices and leveraging sorting for efficienc…

Easy
1491

Average Salary Excluding the Minimum and Maximum Salary

Calculate the average salary of employees, excluding the highest and lowest salaries, from an array of unique salaries.

Easy
1502

Can Make Arithmetic Progression From Sequence

Determine if a given array can be rearranged into a valid arithmetic progression using sorting and consecutive differenc…

Easy
1619

Mean of Array After Removing Some Elements

Calculate the trimmed mean by removing the lowest and highest 5% of elements in an array using sorting for accuracy and …

Easy
1637

Widest Vertical Area Between Two Points Containing No Points

Find the maximum width of a vertical area between points with no points inside using array sorting efficiently.

Easy
1834

Single-Threaded CPU

Simulate task processing with a single-threaded CPU by sorting and prioritizing tasks based on arrival and processing ti…

Medium
1887

Reduction Operations to Make the Array Elements Equal

Find the minimum number of operations to make all array elements equal by reducing the largest elements to the next smal…

Medium
1913

Maximum Product Difference Between Two Pairs

Find the maximum product difference between two pairs in an integer array using sorting for optimal selection.

Easy
2148

Count Elements With Strictly Smaller and Greater Elements

Count elements in an array that have both strictly smaller and strictly greater numbers using array sorting efficiently.

Easy
2164

Sort Even and Odd Indices Independently

Rearrange a 0-indexed array by sorting even and odd indices independently for predictable order and correctness.

Easy
2191

Sort the Jumbled Numbers

Sort numbers based on a custom mapping of their digits, leveraging array manipulation and sorting techniques.

Medium

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Array plus Sorting LeetCode Pattern: 42 Solutions