Problem :
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,val
, we need to prepend it with &
sign. E.g., &val
returns the memory address of val
.
This memory address is assigned to a pointer and can be shared among various functions. E.g. int* p = &val
will assign the memory address of val
to pointer p
. 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 val
and any modification to it will be reflected at the source (val
).
void increment(int *v) {
(*v)++;
}
int main() {
int a;
scanf("%d", &a);
increment(&a);
printf("%d", a);
return 0;
}
You have to complete the function void update(int *a,int *b
), which reads two integers as argument, and sets a
with the sum of them, and b
with the absolute difference of them.
a' = a + b
b' = |a - b|
Input Format :
Input will contain two integers, a
and b
, separated by a newline.
Output Format :
You have to print the updated value of a
and b
, on two different lines.
P.S.: Input/output 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 :
a' = 4 + 5 = 9
b' = |4 - 5| = 1
Solution :
#include <stdio.h>
void update(int *a,int *b) {
int x = 0;
x = *a + *b;
*b = *a - *b;
*a = x;
if (*b < 0)
*b = *b / -1;
}
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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