题目
Implement strstr()
Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Example:
Input: haystack = "hello", needle = "ll"
Output: 2
答案
class Solution {
public int strStr(String haystack, String needle) {
if(needle.equals("")) return 0;
for(int i = 0; i < haystack.length(); i++) {
char h = haystack.charAt(i);
int j = 0;
if(i + needle.length() <= haystack.length() && h == needle.charAt(0)) {
for(j = 0; j < needle.length(); j++) {
if(needle.charAt(j) != haystack.charAt(i + j))
break;
}
if(j == needle.length()) return i;
}
}
return -1;
}
}
