KMP算法-Java实现

public class KMPTest {

    public static void main(String[] args) {
        String s  = "abababb";
        String t = "abb";
        int m = s.length(), n = t.length();
        s = " " + s;
        t = " " + t;
        char[] sArr = s.toCharArray();
        char[] tArr = t.toCharArray();
        int[] ne = new int[n+1];
        int pos = -1;

        for(int i=2,j=0;i<=n;i++) {
            while(j != 0 && tArr[i] != tArr[j+1]) j = ne[j];
            if(tArr[i] == tArr[j+1]) j++;
            ne[i] = j;
        }

        for(int i=1, j=0; i<=m;i++)
        {
            while(j!=0 && sArr[i] != tArr[j+1]) j = ne[j];
            if(sArr[i] == tArr[j+1]) j++;
            if(j == n) {
                pos = i - n;
                break;
            }
        }

        if(pos == -1) System.out.println("Not Found");
        else System.out.println("Found, pos = " + pos);




    }
}