Java > Recursion-1 > countX (CodingBat Solution)

Problem:

Given a string, compute recursively (no loops) the number of lowercase 'x' chars in the string.

countX("xxhixx") → 4
countX("xhixhix") → 3
countX("hi") → 0


Solution:

public int countX(String str) {
  if (str.equals("")) return 0;
  if (str.charAt(0) == 'x') return 1 + countX(str.substring(1));
  else return countX(str.substring(1));
}

4 comments:

  1. MikhailFebruary 15, 2019 at 11:35 AM

    public int countX(String str) {
    int i = str.indexOf("x");
    if (i != -1) {
    return 1 + countX(str.substring(i + 1));
    }
    else
    return 0;
    }

    ReplyDelete
  2. Ashish RaghuvanshiSeptember 14, 2019 at 11:31 PM

    public int countX(String str) {
    int counter=0;
    if(counter==str.length()){
    return 0;
    }

    if(str.charAt(counter)=='x')
    {
    counter=counter+1;

    }
    return counter+countX(str.substring(1));
    }

    ReplyDelete
  3. ioannisaDecember 10, 2019 at 2:00 AM

    public int countX(String str) {
    if (str.isEmpty())
    return 0;

    int x = str.charAt(0)=='x' ? 1 : 0;

    return x + countX(str.substring(1));
    }

    ReplyDelete
  4. Shirinov IlyosbekFebruary 27, 2022 at 6:45 AM

    int count=0;
    for (int i = 0; i < str.length(); i++) {
    if(str.charAt(i)=='x')
    count++;
    }
    return count;

    ReplyDelete