Solution Review: Problem Challenge 1

Next Interval (hard)

Given an array of intervals, find the next interval of each interval. In a list of intervals, for an interval i its next interval j will have the smallest ‘start’ greater than or equal to the ‘end’ of i.

Write a function to return an array containing indices of the next interval of each input interval. If there is no next interval of a given interval, return -1. It is given that none of the intervals have the same start point.

Example 1:

Input: Intervals [[2,3], [3,4], [5,6]]
Output: [1, 2, -1]
Explanation: The next interval of [2,3] is [3,4] having index ‘1’. Similarly, the next interval of [3,4] is [5,6] having index ‘2’. There is no next interval for [5,6] hence we have ‘-1’.

Example 2:

Input: Intervals [[3,4], [1,5], [4,6]]
Output: [2, -1, -1]
Explanation: The next interval of [3,4] is [4,6] which has index ‘2’. There is no next interval for [1,5] and [4,6].

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

Solution Review: Problem Challenge 1

Next Interval (hard)

Solution