Tap here to switch tabs
Problem
Submissions
Problem: Find the Index of the First Occurrence in a String
med
30 min
Explore how to apply the sliding window pattern to identify the first occurrence index of a substring in a given string. This lesson helps you understand substring search problems, constraints, and how to implement an efficient solution using Python.
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
Constraints:
haystack.length,needle.lengthhaystackandneedleconsist of only lowercase English characters
Examples
Understand the problem
Figure it out!
Try it yourself
Similar Problems
Count Substrings With K-Frequency Characters II
Substring with Concatenation of All Words
Binary Subarrays With Sum
Permutation in String
Number of Substrings Containing All Three Characters
Max Consecutive Ones III
Longest Subarray With Diff At Most Limit
Subarray Product Less Than K
Repeated DNA Sequences
Sliding Window Maximum
Unlock AI-Powered LearningUpgrade to smarter learning with instant explanations of Ask Agent, Personalized Interview Prep, Real-World Projects, 3 AI Mock Interviews per month, and Personalized Paths
⋮
Tap here to switch tabs
Problem
Submissions
Problem: Find the Index of the First Occurrence in a String
med
30 min
Explore how to apply the sliding window pattern to identify the first occurrence index of a substring in a given string. This lesson helps you understand substring search problems, constraints, and how to implement an efficient solution using Python.
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
Constraints:
haystack.length,needle.lengthhaystackandneedleconsist of only lowercase English characters
Examples
Understand the problem
Figure it out!
Try it yourself
Similar Problems
Count Substrings With K-Frequency Characters II
Substring with Concatenation of All Words
Binary Subarrays With Sum
Permutation in String
Number of Substrings Containing All Three Characters
Max Consecutive Ones III
Longest Subarray With Diff At Most Limit
Subarray Product Less Than K
Repeated DNA Sequences
Sliding Window Maximum
Unlock AI-Powered LearningUpgrade to smarter learning with instant explanations of Ask Agent, Personalized Interview Prep, Real-World Projects, 3 AI Mock Interviews per month, and Personalized Paths