What is the output the given C language code snippet? #include<stdio.h> int main() { int x[] = {10,20,30}; int *p = x; p++; printf("%d",*p); return 0; }
20
This snippet demonstrates pointer arithmetic on an array. In C, the name of an array (here x) decays to the address of its first element, and adding to a pointer moves it by whole elements, not by single bytes.
Tracing the execution:
int x[] = {10, 20, 30};— three integers are stored contiguously, at indices 0, 1 and 2.int *p = x;—pis set to the address ofx[0], so*pwould be 10.p++;— this is the key step. Incrementing anintpointer advances it bysizeof(int)bytes, i.e. by exactly one array element. Sopnow points tox[1].printf("%d", *p);— dereferencing givesx[1], which is 20.
Why the other outputs are wrong: 10 would be printed only if p had not been incremented (still pointing at x[0]). 30 would need two increments to reach x[2], but p++ advances just one element. A garbage value would arise only if p were moved past the end of the array (out of bounds); here it still points to a valid element, so the result is the well-defined value 20.
Important Questions from Array
Which of the following initialization statement store six integer values in array?
Which of the following expression will delete the entire array pointed to by q?
Consider the following C program segment.
#include <stdio.h>
int main()
{
char s1[7] = "1234";
char *p;p = s1 + 2;
*p = '0';printf("%s", s1);
return 0;
What will be printed by the program?
}#include <stdio.h> void foo(int *p, int x){ *p = x; } int main(){ int *z; int a = 20, b = 25; z = &a; foo(z, b); printf("%d", a); return 0; }The output of the given C program is __________. (Answer in integer)- Consider an array $A$ of integers of size $n$. The indices of $A$ run from 1 to $n$. An algorithm is to be designed to check whether $A$ satisfies the condition given below.
$\forall i,j \in \{1, \dots, n-1\}$ such that $i > j$, $(A[i + 1] - A[i]) > (A[j + 1] - A[j])$
Which one of the following gives the worst case time complexity of the fastest algorithm that can be designed for the problem?
