['a','b','c','d','f'] -> 'e'
['O','Q','R','S'] -> 'P'

找出陣列中跳過的英文字母

想法：
已知char a~z & A~Z 對應 int 97~122 & 65~90
故可透過找到跳過的int數值再轉成char輸出

public class Kata
{
  public static char findMissingLetter(char[] array)
  {
        char lossWord=' ';
        for (int i=0;i< array.length;i++){
            if(((int)array[i]+1)==array[i+1]){

            }else {
                lossWord= (char)((int)array[i]+1);
                return lossWord;
            }
        }
        return lossWord;
  }
}

另種採用foreach循環

public class Kata
{
  public static char findMissingLetter(char[] array){
    char expectableLetter = array[0];
    for(char letter : array){
      if(letter != expectableLetter) break;
      expectableLetter++;
    }
    return expectableLetter;
  }
}