Talk about a project in depth.\nJava basic questions - inner class, mutex vs semaphore.\n\nVariant of https://leetcode.com/problems/letter-combinations-of-a-phone-number/description/\n\nGiven the standard mapping from English letters to digits on a phone keypad (1 \u2192 ""      2 -> a,b,c         3 -> d,e,f      4 -> g,h,i     5 -> j,k,l     6 -> m,n,o      7 -> p,q,r,s     8 -> t,u,v     9 -> w,x,y,z),\n\n write a program that outputs all words that can be formed from any n-digit phone number from the list of given KNOWN_WORDS considering the mapping mentioned above.\n\nKNOWN_WORDS= [\'careers\', \'linkedin\', \'hiring\', \'interview\', \'linkedgo\']\n \n phoneNumber: 2273377\n Output: [\'careers\']\n2273377\n22\n[]\n\n phoneNumber: 54653346\n Output: [\'linkedin\', \'linkedgo\']\n \n Follow up: Add functions for adding and removing words from known words.\n

Talk about a project in depth.\nJava basic questions - inner class, mutex vs semaphore.\n\nVariant of https://leetcode.com/problems/letter-combinations-of-a-pho