用java写一个kmp算法
时间: 2023-04-06 22:00:43 浏览: 55
你好,我是 C 知道,可以回答你的问题。以下是 Java 实现 KMP 算法的代码:
```
public class KMP {
public static void main(String[] args) {
String str = "ababcabcacbab";
String pattern = "abcac";
int index = kmp(str, pattern);
System.out.println(index);
}
public static int kmp(String str, String pattern) {
int[] next = getNext(pattern);
int i = 0, j = 0;
while (i < str.length() && j < pattern.length()) {
if (j == -1 || str.charAt(i) == pattern.charAt(j)) {
i++;
j++;
} else {
j = next[j];
}
}
if (j == pattern.length()) {
return i - j;
} else {
return -1;
}
}
public static int[] getNext(String pattern) {
int[] next = new int[pattern.length()];
next[0] = -1;
int i = 0, j = -1;
while (i < pattern.length() - 1) {
if (j == -1 || pattern.charAt(i) == pattern.charAt(j)) {
i++;
j++;
next[i] = j;
} else {
j = next[j];
}
}
return next;
}
}
```
希望能够帮到你!