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Introduction

In problems where we deal with sorted arrays (or LinkedLists) and need to find a set of elements that fulfill certain constraints, the Two Pointers approach becomes quite useful. The set of elements could be a pair, a triplet or even a subarray. For example, take a look at the following problem:

Given an array of sorted numbers and a target sum, find a pair in the array whose sum is equal to the given target.

To solve this problem, we can consider each element one by one (pointed out by the first pointer) and iterate through the remaining elements (pointed out by the second pointer) to find a pair with the given sum. The ...

Introduction

Pattern: Sliding Window

Pattern: Two Pointers

Pattern: Fast and Slow Patterns

Pattern: Merge Intervals

Pattern: Cyclic Sort

Pattern: In-place Reversal of a LinkedList

Pattern: Tree Breadth First Search

Pattern: Tree Depth First Search

Pattern: Two Heaps

Pattern: Subsets

Pattern: Modified Binary Search

Pattern: Bitwise XOR

Pattern: Top 'K' Elements

Pattern: K-way merge

Pattern : 0/1 Knapsack (Dynamic Programming)

Pattern: Topological Sort (Graph)

Miscellaneous

Conclusions

Introduction