Implement strStr()

28. Implement strStr()

Implement strStr().

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

public class Solution {  
    public int strStr(String haystack, String needle) {
        if (haystack == null || needle == null) {
            return -1;
        }
        if (needle.length() == 0) {
            return 0;
        }
        for (int i = 0; i <= haystack.length() - needle.length(); i++) {
            for (int j = 0; j < needle.length(); j++) {
                if (haystack.charAt(i + j) != needle.charAt(j)) {
                    break;
                }
                if (j == needle.length() - 1) {
                    return i;
                }
            }
        }
        return -1;
    }
}

Hope this helps,
Michael

作者：Michael's Blog

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原文地址：Implement strStr(), 感谢原作者分享。