Pointer in C++ HackerRank Solution
In this lesson, we have solved the pointer in c++ problem of HackerRank.
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, but it does not have ownership.
In order to access the memory address of a variable, val, prepend it with & sign. For example, &val returns the memory address of val.
This memory address is assigned to a pointer and can be shared among functions. For example, int *p = &val will assign the memory address of val to pointer p. To access the content of the memory pointed to, prepend the variable name with a *. For example, *p will return the value stored in val and any modification to it will be performed on val.
void increment(int *v) {
(*v)++;
}
int main() {
int a;
scanf("%d", &a);
increment(&a);
printf("%d", a);
return 0;
}
Function Description
Complete the update function in the editor below.
update has the following parameters:
-
int *a: an integer
-
int *b: an integer
Returns
-
The function is declared with a void return type, so there is no value to return. Modify the values in memory so that a contains their sum and b contains their absoluted difference.
-
a' = a+b
-
b' = |a-b|
Input Format
The input will contain two integers, a and b, separated by a newline.
Sample Input
4
5
Sample Output
9
1
Explaination
-
a’ = 4 + 5 = 9
-
b’ = | 4 – 5 | = 1
Solution
#include <stdio.h>
void update(int *a,int *b) {
int sum = *a+*b;
int subtract;
if(*a>*b)
{
subtract = *a-*b;
}
else
{
subtract = *b-*a;
}
*a = sum;
*b = subtract;
}
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;
}
