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package com.fishercoder.solutions;

/**Implement strStr().

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

public class _28 {

/**You could use substring as follows, or use two pointers to go through the haystack, if substring API call is not allowed.*/

public static int strStr(String haystack, String needle) {

if(haystack == null || needle == null || haystack.length() < needle.length()) return -1;

for(int i = 0; i <= haystack.length() - needle.length(); i++){

if(haystack.substring(i, i+needle.length()).equals(needle)) return i;

}

return -1;

}

public static void main(String...args){

// String haystack = "a";

// String needle = "";

// String haystack = "mississippi";

// String needle = "a";

String haystack = "a";

String needle = "a";

strStr(haystack, needle);

}