leetcode Question 42: Letter Combinations of a Phone Number. Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below.
The Battle of the Little Bighorn, known to the Lakota and other Plains Indians as the Battle of the Greasy Grass and commonly referred to as Custer's Last Stand, was an armed engagement between combined forces of the Lakota, Northern Cheyenne, and Arapaho tribes and the 7th Cavalry Regiment of the United States Army.
The Army's coordination and planning began to go awry on June 17, 1876, when Crook's column retreated after the Battle of the Rosebud, just 30 miles to the southeast of the eventual Little Bighorn battlefield.