KMP算法（java代码）

package text_seven_suanfa;

import java.util.Arrays;

public class KMPSearch {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String str1="abcabd";
		String str2="abd";
		int[] a={0,1,0};
		System.out.println(Arrays.toString(kmpNext(str2)));
		System.out.println(kmpSearch(str1,str2,kmpNext(str2)));
	}
	
	//KMP搜索算法
	public static int kmpSearch(String str1,String str2,int[] next){
		for(int i=0,j=0;i<str1.length();i++){
			if(j>0&&str1.charAt(i)!=str2.charAt(j)){
				j=next[j-1];
			}
			if(str1.charAt(i)==str2.charAt(j)){
				j++;
			}
			if(j==str2.length()){
				return i-j+1;
			}
		}
		return -1;
	}
	
	//获取字符串的部分匹配值表
	public static int[] kmpNext(String dest){
		int[] next=new int[dest.length()];
		for(int i=1,j=0;i<dest.length();i++){
			if(j>0&&dest.charAt(i)!=dest.charAt(j)){
				j=next[j-1];
			}
			if(dest.charAt(i)==dest.charAt(j)){
				j++;
			}
			next[i]=j;
		}
		return next;
	}
	
	
	//暴力求解
	public static int baoliSearch(String str1,String str2){
		char[] s1=str1.toCharArray();
		char[] s2=str2.toCharArray();
		int i=0;
		int j=0;
		while(i<s1.length&&j<s2.length){
			if(s1[i]==s2[j]){
				i++;
				j++;
			}else{
				i=i-j+1;
				j=0;
			}
		}
		if(j==s2.length)
			return i-j+1;
		else
			return -1;
	}

}