[LeetCode] Implement strStr()

문제

Implement strStr().

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

Example 1:

Input: haystack = "hello", needle = "ll" Output: 2

Example 2:

Input: haystack = "aaaaa", needle = "bba" Output: -1

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().

 

Approach

string find()가 이 문제 해결 그 자체이다. 없으면 npos고 있으면 시작 인덱스를 알려주기 때문에...

나는 새롭게 substr로 풀어보았다.

이게 무슨 의미가 있는 문제인가

 

Code

https://github.com/chi3236/algorithm/blob/master/LeetCode_Implement_strStr().cpp

chi3236/algorithm