Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns in C++

Solution: Find the Index of the First Occurrence in a String

Explore the sliding window approach to identify the first occurrence index of a substring within a string. Understand how to implement fixed-size windows for character-by-character comparison, optimizing your solution with clear time and space complexity considerations.

We'll cover the following...

Statement

Given two strings haystack and needle, return the index of the first occurrence of needle within haystack. If needle does not exist as a substring of haystack, return −1-1.

Constraints:

  • 1≤1 \leq haystack.length, needle.length ≤104\leq 10^4

  • haystack and needle consist of only lowercase English characters

Solution

The key intuition behind this solution is to use a fixed-size sliding window of length equal to needle ...