字符串匹配算法KMP Java实现

import java.util.Arrays;

public class KMPSearch {
public static int[] table;
public static void generateTab(String key){//查询字串生成偏移对照表，一次迭代就可以
int len=key.length();
table=new int[len];
Arrays.fill(table, 0);
for(int i=1;i<len;i++){
if(key.charAt(i)==key.charAt(table[i-1])){
table[i]=table[i-1]+1;
}
}
}
public static int KMPSearchs(String doc,String key){
generateTab(key);
int result=-1;
int doc_size=doc.length(),
key_size=key.length(),
doc_iter=0,
key_iter=0;
while(doc_iter<doc_size){//遍历所查询的文档，同样，单层循环就可以实现→_→
if(doc.charAt(doc_iter)==key.charAt(key_iter)){
doc_iter++;
key_iter++;
}else{
if(key_iter==0){
doc_iter++;
continue;
}else{
key_iter=table[key_iter-1];
continue;
}
}
if(key_iter==key_size){
result=doc_iter-key_size;
break;
}
}
return result;
}
public static void main(String[] args){
int i=KMPSearchs("bbc abcdab abcdabcdabde","abcdabd");
System.out.println(i);
}
}