Package g0001_0100.s0028_find_the_index_of_the_first_occurrence_in_a_string

Class Solution

java.lang.Object
g0001_0100.s0028_find_the_index_of_the_first_occurrence_in_a_string.Solution
public class Solution extends java.lang.Object
28 - Implement strStr().

Easy

Implement strStr().

Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

Clarification:

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().

Example 1:

Input: haystack = “hello”, needle = “ll”

Output: 2

Example 2:

Input: haystack = “aaaaa”, needle = “bba”

Output: -1

Example 3:

Input: haystack = "", needle = ""

Output: 0

Constraints:

  • 0 <= haystack.length, needle.length <= 5 * 104
  • haystack and needle consist of only lower-case English characters.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    strStr(java.lang.String haystack, java.lang.String needle)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • strStr

      public int strStr(java.lang.String haystack, java.lang.String needle)