Pointer in C HackerRank Solutions

Objective

In this challenge, you will learn to implement the basic functionalities of pointers in C. A pointer in C is a way to share a memory address among different contexts (primarily functions). They are primarily used whenever a function needs to modify the content of a variable that it does not own.

In order to access the memory address of a variable, , prepend it with  sign. For example, &val returns the memory address of .

This memory address is assigned to a pointer and can be shared among various functions. For example,  will assign the memory address of  to pointer . To access the content of the memory to which the pointer points, prepend it with a *. For example, *p will return the value reflected by  and any modification to it will be reflected at the source ().

	void increment(int *v) {
        (*v)++; 
    }
      	int main() {
        int a;
        scanf("%d", &a);
        increment(&a);
        printf("%d", a);
    	return 0;      
    }     

Task

Complete the function void update(int *a,int *b). It receives two integer pointers, int* a and int* b. Set the value of  to their sum, and  to their absolute difference. There is no return value, and no return statement is needed.

Input Format

The input will contain two integers,  and , separated by a newline.

Output Format

Modify the two values in place and the code stub main() will print their values.

Note: Input/ouput will be automatically handled. You only have to complete the function described in the 'task' section.

Sample Input

4
5

Sample Output

9
1

CODE

#include <stdio.h>

void update(int *a,int *b) {

    // Complete this function

    int sum=0, diffmod=0;

    /* calculate sum and diff */

    sum = *a + *b;

    diffmod = *a - *b;

    /* if diff is less then zero multiply -1 to get absolute

       diff or we can use abs() function from standalib     */

    if(diffmod<0)

      diffmod = diffmod*(-1);

    *a = sum;

    *b = diffmod;

}

int main() {

    int a, b;

    int *pa = &a, *pb = &b;

   

    scanf("%d %d", &a, &b);

    update(pa, pb);

    printf("%d\n%d", a, b);

    return 0;

}

 Thank You