leetcode_gym/_problems/implement_strstr.md

layout, title, last_solved, category, leetcode_url, status

layout	title	last_solved	category	leetcode_url	status
page	Implement strstr		string	https://leetcode.com/problems/implement-strstr	Attempted

Problem

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

Solution

{% highlight python %}

def strStr(self, haystack: str, needle: str) -> int:
    
    # "hello" "ll"
    
    if not needle: return 0
    
    for i in range(len(haystack)):
        
        if haystack[i]==needle[0]:
            
            substr = haystack[i:i+len(needle)]
            
            if substr==needle:
                
                return i
    
    
    return -1

{% endhighlight %}