KMP

package com.blog;


public class KmpTest {
	public static void main(String[] args) {
		//BBC ABCDAB ABCDABCDABDE
		//ABCDABD
		char[] parent = new String("BBC ABCDAB ABCDABCDABDE").toCharArray();
		char[] son = new String("ABCDABD").toCharArray();
		int[] next = getnext(son);
		int i = 0;
		int j = 0;
		for (i = 0; i < parent.length; i++) {
			while (j > 0 && parent[i] != son[j]) {
				j = next[j-1];
			} 
		    
			if (son[j] == parent[i]) {
				j++;
			}
			
			if (j == son.length) {
				System.out.println("find the result --->" + (i - j) + "--->" + parent[i - j] );
				break;
			}
		}
		
		
	}

	
	public static int[] getnext(char[] s) {
		int[] next = new int[s.length];
		int len;
		int i, j;
		len = s.length;
		i = 0;
		j = 0;
		while (i < len) {
			next[i] = j;
			System.out.println(i + "--->" + j);
			if (j == 0 || s[i] != s[j - 1]) {
				j = 0;
			}
			++i;
			++j;
		}
		return next;
	}
}