codingbat recursion Given a string, compute recursively (no loops) the number of "11" substrings in the string. The "11" substrings should not overlap.

Given a string, compute recursively (no loops) the number of "11" substrings in the string. The "11" substrings should not overlap.


solution

public int count11(String str) {
  return count(str,0);
}
int count(String str,int index)
{
  if(str.length()-index<=1|| str.length()<2)
    return 0;
  else if(str.charAt(index)=='1' && str.charAt(index+1)=='1')
  {
   return 1+count(str,index+2);
  }
  else
  {
    return count(str,index+1);
  }
}