https://leetcode.com/problems/implement-strstr/
Difficulty: Easy
Implement strStr().
Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Input: haystack = "hello", needle = "ll"
Output: 2
Input: haystack = "aaaaa", needle = "bba"
Output: -1
What should we return when needle
is an empty string? This is a great question to ask during an interview.
For the purpose of this problem, we will return 0 when needle
is an empty string. This is consistent to C's strstr()
and Java's indexOf()
.
Related Topics:
Two Pointers
, String