[Array and String] Implement strStr()

[Array and String] Implement strStr()

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.

/** * @param {string} haystack * @param {string} needle * @return {number} */ var strStr = function(haystack, needle) { if (needle === '') return 0; else { if (haystack.includes(needle)) { for (let i = 0; i < haystack.length; i++) { if (needle === haystack.substring(i, needle.length + i)) return i; } } else { return -1; } } };

https://leetcode.com/explore/learn/card/array-and-string/203/introduction-to-string/1161/

from http://bomiismybestie.tistory.com/63 by ccl(A) rewrite - 2021-12-16 11:27:48