Java 字符串匹配的KMP算法

package Four;

import java.util.Scanner;

/***
 * 字符型的kmp算法
 * @author bai
 *	描述：
 *		给你一个文本串，再给你一个模式串，
 *		文本串中有多少个子串的模式串完全匹配
 */
public class StringKmp {
	
	static int[] nextTable = new int[10000];
	
	public static void getNextTable(String pattern){
		char[] patt = pattern.toCharArray();
		int m = patt.length;
		int j =0;
		nextTable[j] = -1;
		int i = nextTable[j];
		while(j<m){
			if(i==-1||patt[j]==patt[i]){
				i++;
				j++;
				nextTable[j]= i;
			}else{
				i = nextTable[i];
			}
		}
		return;
	}
	public static int KMP(String text,String pattern){
		getNextTable(pattern);
		char[] t = text.toCharArray();
		int n = t.length;
		char[] p = pattern.toCharArray();
		int m  = p.length;
		int i = 0;
		int j = 0;
		int number = 0;
		while(i<n){
			if(j==-1||t[i]==p[j]){
				i++;
				j++;
			}else{
				j = nextTable[j];
			}
			if(j==m){
				number++;
				j=nextTable[j];
			}
		}
		return number;
	}
	
	public static void main(String[] args) {
		int caseNumber;
		Scanner scan  = new Scanner(System.in);
		System.out.print("caseNumber: ");
		caseNumber = scan.nextInt();
		while((caseNumber--)>0){			
			System.out.println("text:");
			String text = scan.next();
			System.out.println("pattern:");
			String pattern = scan.next();
			System.out.println(KMP(text,pattern));
		}
		
	}
}

来源：CSDN

作者：gldbys

链接：https://blog.csdn.net/gldbys/article/details/104671756