I have three different C files, however I DO NOT need to edit the main or header. I need to complete the 3rd file below so that, given a bit string 'n' and a number of bits 'b' chosen by the user, it sign extends the number 'n' to fill up exactly 'b' bits and then negates that binary number. Comments are helpful...Also

- only edit the .c file (not main or header)

- the getBitString function must use the getchar function to let the user enter one charecter

- signExtend does not need to check for errors in its arguments

- the negate function should be just a two step algorithm to negate the given binary number

Example Output:

//header

#ifndef LAB4 #define LAB4

static const int MAX_WIDTH = 16; // the maximum number of bits in numbers

int getBitString(char input[]); void signExtend(int n, char input[], char output[]); void negate(int num_bits, char input[], char output[]);

#endif

//main

#include

#include "lab4.h"

int main(void) { char input[MAX_WIDTH + 1]; // bits entered by the user int input_length = 0; // number of bits entered by the user

char number[MAX_WIDTH + 1]; // user input after sign extension int num_bits = 0; // number of bits after sign extension

char negated[MAX_WIDTH + 1]; // result of negating number printf("Enter an integer in binary with up to 16 bits: "); input_length = getBitString(input);

num_bits = -1; while (num_bits MAX_WIDTH ) { printf("Choose the number of bits between %d and %d: ", input_length,MAX_WIDTH); scanf("%d",&num_bits); }

signExtend(num_bits, input, number); printf(" n = %s ",number);

negate(num_bits,number,negated);

printf("-n = %s ",negated); return 0; }// main

//FILE TO EDIT

#include #include #include

#include "lab4.h"

/* Wait for the user to enter between 0 and MAX_WIDTH bits followed by a newline character, and store these bits in the input array as a null terminated string. If the user enters more than MAX_WIDTH characters, then the user's input is truncated to MAX_WIDTH bits. Return the number of bits entered by the user (not counting the newline character) You can assume that input is large enough to store the input string. */ int getBitString(char input[]) {

/* to be completed */

return 0; // this line should be modified }// getBitString

/* Given an input bit string and an integer n greater than or equal to the length of input, store in output a copy of the input bit string after sign-extending it to n bits You can assume that output is large enough to store the sign-extended input string. */ void signExtend(int n, char input[], char output[]) {

/* to be completed */

}// signExtend

/* given an input bit string representing an integer n in two's complement representation of length num_bits, store in output the num_bits long two's complement representation of -n */ void negate(int num_bits, char input[], char output[]) {

/* to be completed */ }// negate

Enter an integer in binary with up to 16 bits: 0101 Choose the number of bits between 4 and 16: 6 n 000 101 Enter an integer in binary with up to 16 bits: 0101 Choose the number of bits between 4 and 16: 6 n 000 101