📘

Implement strStr

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

Input:

sadbutsad
sad

Output:

Reasoning:

The function strStr checks if the substring needle ("sad") exists in the string haystack ("sadbutsad")
It starts by comparing the first character of needle with the first character of haystack, finding a match
Since the rest of the characters in needle also match the subsequent characters in haystack, it confirms the presence of needle at the starting index
The function returns the index where the match is found, which is $0$ in this case, as the needle is found at the beginning of the haystack

Editor

Python 3.13.1

0/0

Run code to see test results.

📘

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

Input:

sadbutsad
sad

Output:

Reasoning:

The function strStr checks if the substring needle ("sad") exists in the string haystack ("sadbutsad")
It starts by comparing the first character of needle with the first character of haystack, finding a match
Since the rest of the characters in needle also match the subsequent characters in haystack, it confirms the presence of needle at the starting index
The function returns the index where the match is found, which is $0$ in this case, as the needle is found at the beginning of the haystack

Editor

Python 3.13.1

0/0

Run code to see test results.