consecutiveArray.txt

Challenge:

You are given an array(list) strarr of strings and an integer k. Your task is to return the first longest string consisting of k consecutive strings taken in the array.

Examples:
strarr = ["tree", "foling", "trashy", "blue", "abcdef", "uvwxyz"], k = 2

Concatenate the consecutive strings of strarr by 2, we get:

treefoling   (length 10)  concatenation of strarr[0] and strarr[1]
folingtrashy ("      12)  concatenation of strarr[1] and strarr[2]
trashyblue   ("      10)  concatenation of strarr[2] and strarr[3]
blueabcdef   ("      10)  concatenation of strarr[3] and strarr[4]
abcdefuvwxyz ("      12)  concatenation of strarr[4] and strarr[5]

Two strings are the longest: "folingtrashy" and "abcdefuvwxyz".
The first that came is "folingtrashy" so 
longest_consec(strarr, 2) should return "folingtrashy".

In the same way:
longest_consec(["zone", "abigail", "theta", "form", "libe", "zas", "theta", "abigail"], 2) --> "abigailtheta"
n being the length of the string array, if n = 0 or k > n or k <= 0 return "" (return Nothing in Elm, "nothing" in Erlang).

Note
consecutive strings : follow one after another without an interruption

-----------------

Solution:

class LongestConsec {
    
    public static String longestConsec(String[] strarr, int k) {
      if (strarr.length == 0 || k <= 0 || k > strarr.length) {
          return "";
      }

      String result = "";

      for (int i = 0; i <= strarr.length - k; i++) {
          StringBuilder sb = new StringBuilder();
          for (int j = i; j < i + k; j++) {
              sb.append(strarr[j]);
          }

          String temp = sb.toString();
          if (temp.length() > result.length()) {
              result = temp;
          }
      }

      return result;
    }
}