Hackerrank Pointer Solution

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, of which it doesn't have ownership.

In order to access the memory address of a variable, , we need to prepend it with  sign. E.g., &val returns the memory address of .

This memory address is assigned to a pointer and can be shared among various functions. E.g.  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;
}  

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You have to complete the function void update(int *a,int *b), which reads two integers as argument, and sets  with the sum of them, and  with the absolute difference of them.

Input Format

Input will contain two integers,  and , separated by a newline.

Output Format

You have to print the updated value of  and , on two different lines.

P.S.: Input/ouput will be automatically handled. You only have to complete the void update(int *a,int *b) function.

Sample Input

4
5

Sample Output

9
1

Explanation

Solution in cpp

Approach 1.

#include <stdio.h>
#include <stdlib.h>

void update(int *a,int *b) {
    int temp=*a;
    *a=*a+*b;
    *b=abs(temp-(*b));
}

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;
}

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Approach 2.

#include <stdio.h>
#include <stdlib.h>

void update(int *a,int *b) {
    int temp = *a;
    *a = *a + *b;
    *b = abs(temp - *b);
}

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;
}

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Approach 3.

#include <stdio.h>
#include<math.h>
void update(int *a,int *b) {
    // Complete this function 
    int c;
    c=*a;
    *a=(*a)+(*b);
    *b=fabs(c-(*b));
}

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;
}

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