In this Pointers in C HackerRank Solution, we 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
Explanation
Pointers in C HackerRank Solution 1
#include <stdio.h>
#include<math.h>
void update(int *a,int *b) {
// Complete this function
int max,diff;
max=*a+*b;
diff=abs(*a-*b);
printf("%d\n%d", max, diff);
}
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;
}Explanation:
*pa store the address of a , *pb store the address of b. In pa, store the value of a which is given by user and similarly pb store a value of b. calling the function update by passing the argument of value of pa and pb. because *pa and *pb is pointer then the function update (int *a, int *b) called. the prototype of the function update is void update(int *, int *); take variable one for summation i.e. max and another one for difference i.e. diff. max=*a+*b; *a means Value at Address , similarly for *b . then add both the values. now for difference, diff=abs(*a-*b); abs is a function of absolute that dissolve the negative sign which in math.h header file, i used it because of our output , need only positive difference so i used it. You can not used if it not needed. Hope I will able to explain you for your better understand.
2 lines Solution – Solution 2
void update(int *a,int *b) {
// Complete this function
*a=*a+*b;
*b=abs(*a-(2**b));
}Solve original Problem on HackerRank here. Checkout more HackerRank Problems