KMP算法-JAVA代码

 1 import java.util.Arrays;
 2  
 3 public class Test {
 4  
 5     /**
 6      * @param str 文本串
 7      * @param dest 模式串
 8      * @param next 匹配核心数组
 9      * @return
10      */
11     public static int kmp(String str, String dest,int[] next) {
12         for(int i = 0, j = 0; i < str.length(); i++){
13             if (j > 0 && str.charAt(i) != dest.charAt(j)) {
14                 j = next[j - 1];
15             }
16             if (str.charAt(i) == dest.charAt(j)) {
17                 j++;
18             }
19             if (j == dest.length()) {
20                 return i-j+1;
21             }
22         }
23         return 0;
24     }
25  
　　　　
26     public static int[] kmpnext(String dest) {
27         int[] next = new int[dest.length()];
28         next[0] = 0;
29         for(int i = 1,j = 0; i < dest.length(); i++) {
30             if (j > 0 && dest.charAt(j) != dest.charAt(i)) {
31                 j = next[j - 1];
32             }
33             if (dest.charAt(i) == dest.charAt(j)) {
34                 j++;
35             }
36             next[i] = j;
37         }
38         return next;
39     }
40  
50 }