7.6 lab: checker for integer string forms often allow a user to enter an integer. write a program that takes in a string representing an integer as input, and outputs yes if every character is a digit 0-9. ex: if the input is: 1995 the output is: yes ex: if the input is: 42,000 or any string with a non-integer character, the output is: no

6. the is particularly susceptible to the effects of alcohol because it receives a large portion of total blood flow and has a high concentration of neurons. a. heart b. pancreas c. brain d. liver

Write a program called assignment3 (saved in a file assignment3.java) that computes the greatest common divisor of two given integers. one of the oldest numerical algorithms was described by the greek mathematician, euclid, in 300 b.c. it is a simple but very e↵ective algorithm that computes the greatest common divisor of two given integers. for instance, given integers 24 and 18, the greatest common divisor is 6, because 6 is the largest integer that divides evenly into both 24 and 18. we will denote the greatest common divisor of x and y as gcd(x, y). the algorithm is based on the clever idea that the gcd(x, y) = gcd(x ! y, y) if x > = y and gcd(x, y) = gcd(x, y ! x) if x < y. the algorithm consists of a series of steps (loop iterations) where the “larger” integer is replaced by the di↵erence of the larger and smaller integer. this continues until the two values are equal. that is then the gcd.

Write a modular program (no classes yet, just from what you learned last year), that allows two players to play a game of tic-tac-toe. use a two-dimensional char array with 3 rows and 3 columns as the game board. each element of the array should be initialized with an asterisk (*). the program should display the initial board configuration and then start a loop that does the following: allow player 1 to select a location on the board for an x by entering a row and column number. then redisplay the board with an x replacing the * in the chosen location. if there is no winner yet and the board is not yet full, allow player 2 to select a location on the board for an o by entering a row and column number. then redisplay the board with an o replacing the * in the chosen location. the loop should continue until a player has won or a tie has occurred, then display a message indicating who won, or reporting that a tie occurred. player 1 wins when there are three xs in a row, a column, or a diagonal on the game board. player 2 wins when there are three ox in a row, a column, or a diagonal on the game board. a tie occurs when all of the locations on the board are full, but there is no winner. input validation: only allow legal moves to be entered. the row must be 1, 2, or 3. the column must be 1, 2 3. the (row, column) position entered must currently be empty (i.e., still have an asterisk in it).