Question

Create qz5.c to include all of the following function prototypes:

void check1(char *, char, int *);
void check2(char *, char, int *);
void display(char, int);

Then, implement main() to perform the tasks below:

1. Define a 10-element char array with initial values of any lower case letters of your selection. Values can duplicate.
2. Define a pointer that points to the above array.
3. Print the array completely with double spaces before each character. See screenshot below for a sample.
4. Call check1() with three arguments:
   • First argument is the pointer defined in item 2 above.
   • Second argument is any lower case letter which is used to compared with every element of the input array.
   • Third argument is passed by address (or reference), which tells the total number of elements of the array that are smaller than the letter specified by the second argument. FYI. Letter 'a' is smaller than 'b', and 'b' is smaller than 'c', etc.

check1() must use the pointer given in its first parameter and no direct access of the array to set a value to its third parameter, which can then be accessed by main().

5. Call display() to print two lines of message using the last two arguments of check1(). For example, if 'w' is the 2nd argument of check1(), then there are 8 elements in the given array smaller than 'w' and 2 elements is equal to or greater than 'w'.
6. Repeat task 4 and 5, except check2() is called in task 4 with three same arguments of check1(). Here check2() also uses only the pointer that points to the array to perform exactly the same function as check1() but the way this pointer is used must be different from that of check1(). In the screenshot below, 'b' is passed as the 3rd argument and results zero elements less than 'b' and all ten are either equal to or greater than 'b'.

Answer 1

//******************************************************START OF PROGRAM*****************************************

#include <stdio.h>

void check1(char *, char, int *);
void check2(char *, char, int *);
void display(char, int);

void main(){
char str[10] = {"HomeworkLibster"}, *ptr, letter;
int n = 0; //used to keep track of how many elements grater than or less than input letter is in array
printf("\nEnter the letter to be compared");
scanf("%c", &letter);

ptr = str; // ptr is a pointer pointing to the array str

check1(ptr, letter, &n);
display(letter, n);

check2(ptr, letter, &n);
display(letter, n);
}

void check1(char *ptr, char letter, int *n){
*n = 0; //since n is a pointer, we have to use value at operator '*' to access its value
for(int i = 0; i < 9; i++)
if(ptr[i] < letter)
(*n)++;
}

void check2(char *ptr, char letter, int *n){
*n = 0; //since n is a pointer, we have to use value at operator '*' to access its value
for(int i = 0; i < 9; i++)
if(*(ptr + i) < letter) //uses i as a displacement for accessing values from ptr
(*n)++;
}

void display(char letter, int n){
printf("\nThere are %d elements in the given array lesser than '%c' and %d elements equal to or greater than '%c'", n, letter, 10 - n, letter);
}

//*****************************************************END OF PROGRAM*****************************************************

The above is the implementation of the functions check1() and check2()

check2() uses its character pointer (ptr) in a different way than check1(), because it uses the value at operator '*' and the displacent 'i' to calculate the address of each of its elements and then display its value - *(ptr + i)