LeetCode Daily Notes#

6/3/2020#

• string.trim() is used to trim leading and tailing spaces in a String

• If we want to split a string by multiple spaces we can use string.split(“\\s+”)

• If we want to concatenate a list of string, we can use String.join(“ “, wordList).

• Lambda expression used in sorting List or Array

  arr1.sort((a, b) -> Integer.compare(a[1] - a[0], b[1] - b[0]));
  // or
  arr1.sort(Comparator.comparingInt(a -> a[1] - a[0]));
  // or this method is more flexible
  arr2.sort((a, b) -> {
                  if(a[0] > a[1]) {
                      return 1;
                  } else if (a[0] < a[1]) {
                      return -1;
                  } else {
                      return 0;
                  }
              });