Import java. util. treemap;

public class hw1 {
/**
* inverts an array of strings by returning a treemap that maps strings to the smallest index in the array that contains the string.
*
* @param a an array of strings
* @return a map that given a string returns the smallest index of the array that contains the string
* (or null if string is not in the array a).
*/
public static treemap invert(string[] a) {
//to do
return null;
}

/**
* computes the total number of occurrences of every string in an array.
*
* @param a an array of strings
* @return a map that given a string returns the number of occurrences of that string in the array
* (or null if string is not in the array a).
*/
public static treemap count(string[] a) {
// todo
return null;
}
}

Write a new lc-3 trap subroutine (i. e. a subroutine that will be invoked via the trap instruction) that will receive a numeric digit entered at the keyboard (i. e. an ascii character), echo it to the screen, and return in r0 the corresponding numeric value: so if the user types the digit '7', the character '7' will appear on the screen, but the value returned in r0 will be b0000 0000 0000 0111 (#7) you may not use any trap calls in your code - you must implement the "polling" code that interrogates the keyboard status and data registers. ; getnum_tsr ; a subroutine for obtaining a numeric value ; given ascii numeric digit input to keyboard. ; the numeric digit is echoed to the console (e. g. '7' = b0000 0000 0011 0111), ; but the value returned in r0 is the actual numeric value ; corresponding to the digit (e. g. b0000 0000 0000 0111 =