diff --git a/problems/0028.实现strStr.md b/problems/0028.实现strStr.md index ef7008bc..f0b56719 100644 --- a/problems/0028.实现strStr.md +++ b/problems/0028.实现strStr.md @@ -649,6 +649,41 @@ class Solution { } ``` +```Java +class Solution { + //前缀表(不减一)Java实现 + public int strStr(String haystack, String needle) { + if (needle.length() == 0) return 0; + int[] next = new int[needle.length()]; + getNext(next, needle); + + int j = 0; + for (int i = 0; i < haystack.length(); i++) { + while (j > 0 && needle.charAt(j) != haystack.charAt(i)) + j = next[j - 1]; + if (needle.charAt(j) == haystack.charAt(i)) + j++; + if (j == needle.length()) + return i - needle.length() + 1; + } + return -1; + + } + + private void getNext(int[] next, String s) { + int j = 0; + next[0] = 0; + for (int i = 1; i < s.length(); i++) { + while (j > 0 && s.charAt(j) != s.charAt(i)) + j = next[j - 1]; + if (s.charAt(j) == s.charAt(i)) + j++; + next[i] = j; + } + } +} +``` + Python3: ```python