KMP算法代碼(java版)

JAVA代碼如下:

public class KMP {
	public static void main(String[] args) {
		KMP kmp = new KMP();
		String target="asfsdfssaaabcadsdfaaaaaaaadsf";
		String mode="fsdfss";
		boolean result=kmp.mathString(target, mode);
		if(!result){
			System.out.println("主串:"+target);
			System.out.println("子串:"+mode);
			System.out.println("沒有找到匹配的子串");
		}
		
	}

	public boolean mathString(String target, String mode) {
		int[] next = getNextArray(mode);
		int i = 0;
		int j = 0;
		while (i < target.length() && j < mode.length()) {

			if (j == 0 || target.charAt(i) == mode.charAt(j)) {
				i++;
				j++;
			} else {
				if(next[j]==-1){
					j=0;
					i++;
				}else{
					j=next[j];
				}
			}
			
		}
		if (j == mode.length()){
			System.out.println("主串:"+target);
			System.out.print("子串:");
			for(int t=0;t<i-mode.length();t++){
				System.out.print(" ");
			}
			System.out.println(mode);
			System.out.println("主串匹配的位置從:"+(i-mode.length()+1)+"到"+i);
			return true;
		}
			
		return false;
	}

	public int[] getNextArray(String mode) {
		int j = 0, k = -1;
		int[] next = new int[mode.length()];
		next[0] = -1;
		while (j < mode.length()-1) {
			if (k == -1 || mode.charAt(j) == mode.charAt(k)) {
				++j;
				++k;
				if (mode.charAt(j) != mode.charAt(k)) {
					next[j] = k;
				} else {
					next[j] = next[k];
				}
			}
			else
				k = next[k];
		}
		return next;
	}

}

輸出結果:

主串:asfsdfssaaabcadsdfaaaaaaaadsf
子串:  fsdfss
主串匹配的位置從:3到8

暫時放博客裏存起來，以備不時之需O(∩_∩)O哈！。。。。。