字符串在对应字符串中出现的次数.

class Text4{public static void main(String args[]){String a=new String("dnasdnaicpa");System.out.println(Zfc.fangFa(a,"dna"));}}class Zfc{private static int c=0;public static int fangFa(String a,String b){String x;int k=b.length();for(int i=0;i<=a.length()-1;){ x=new String(a.substring(i,k));if(b.equals(x)){c++;i=i+b.length();k=b.length()+i;}else if(i+b.length()+1==a.length()){i=i+10+b.length();}else{    i++;    k++;}}return c;}}

编写过程中一定要注意substring的越界!!!!

必要时纸上写一写