題目描述

Description
Given number n. Print number from 1 to n. But:

• when number is divided by 3, print “fizz”.

• when number is divided by 5, print “buzz”.

• when number is divided by both 3 and 5, print “fizz buzz”.
  Example
  If n = 15, you should return:

  [
    “1”, “2”, “fizz”,
    “4”, “buzz”, “fizz”,
    “7”, “8”, “fizz”,
    “buzz”, “11”, “fizz”,
   “13”, “14”, “fizz buzz”
  ]

Challenge
Can you do it with only one if statement?
被3整除就fizz，被5整除就buzz，被3和5整除就fizz buzz
題目很簡單，挑戰很有意思，所以就記錄一下。挑戰讓我們只用一個if來寫

思路

這道題呢，當然如果用三元運算子一直巢狀也是可以的，不過明顯不是這道題的意思
剛開始不知道怎麼使用一個if來完美的解決這道題，後來看到一個老哥的解法，覺得還是比較有意思的
是這樣的，寫一個函式helper用來判斷整除，然後用字串拼接來輸出字串：

• 如果被3整除，字串加上“fizz”
• 如果被15整除，加上“ ”
• 如果被5整除，加上“buzz”

String w = helper(i, 3, "fizz") + helper(i, 15, " ")
 + helper(i, 5, "buzz");

程式碼

public List<String> fizzBuzz(int n) {
        List<String> strings = new LinkedList<>();
        for (int i = 1; i <= n; i++) {
            String w = helper(i, 3, "fizz"
 
) + helper(i, 15, " ") + helper(i, 5, "buzz");
            if (w.equals("")) {
                w += i;
            }
            strings.add(w);
        }
        return strings;
    }

    public String helper(int n, int div, String w) {
        return n % div == 0 ? w : "";
    }