C Programming - Arrays - Discussion

Discussion Forum : Arrays - Find Output of Program (Q.No. 2)
2.
What will be the output of the program ?
#include<stdio.h>

int main()
{
    static int a[2][2] = {1, 2, 3, 4};
    int i, j;
    static int *p[] = {(int*)a, (int*)a+1, (int*)a+2};
    for(i=0; i<2; i++)
    {
        for(j=0; j<2; j++)
        {
            printf("%d, %d, %d, %d\n", *(*(p+i)+j), *(*(j+p)+i), 
                                    *(*(i+p)+j), *(*(p+j)+i));
        }
    }
    return 0;
}
1, 1, 1, 1
2, 3, 2, 3
3, 2, 3, 2
4, 4, 4, 4
1, 2, 1, 2
2, 3, 2, 3
3, 4, 3, 4
4, 2, 4, 2
1, 1, 1, 1
2, 2, 2, 2
2, 2, 2, 2
3, 3, 3, 3
1, 2, 3, 4
2, 3, 4, 1
3, 4, 1, 2
4, 1, 2, 3
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
78 comments Page 7 of 8.

Bhavya said:   1 decade ago
Chand explanation is very easily understood and its good.

Vamsy said:   1 decade ago
From the above program ;
a[0][0]=1 we can write as *(a+0) ; Here 'a' points a[0] and(a+0) to a[0][0]
a[0][1]=2 we can write as *(a+1) ; Here 'a' points a[0] and(a+1) to a[0][0]
a[1][1]=3 " " " " *(*(a+1)+0)
a[1][1]=4 *(*(a+1)+1)

The program goes in this manner.....

Neetesh said:   1 decade ago
What about the two dimensional array
a[0][0]=1
a[0][1]=2
a[1][0]=3
a[1][1]=4

i.e. *(*(a+1)+0)=3
*(*(a+0)+1)=2

Is this right??? if yes then please help me to solve it.

Karishma said:   1 decade ago
@Dilip:

There is printing mistake in Step:3 i=1,j=0

Fourth line

*(*(p+j)+i)=*(*(p+0)+0)=*((a)+0)=a[1]=2

Since i=1 in step:3 therefore,it shoud be

*(*(p+j)+i)=*(*(p+0)+1)=*((a)+1)=a[1]=2

Naresh said:   1 decade ago
Thank you Dilip.

I could get perfectly from your explanation.

Dilip said:   1 decade ago
step1:p=0;
step2:i=0,j=0
*(*(p+i)+j)=*(*(p+0)+0)=*((a)+0)=a[0]=1
*(*(j+p)+i)=*(*(0+p)+0)=*((a)+0)=a[0]=1
*(*(i+p)+j)=*(*(0+p)+0)=*((a)+0)=a[0]=1
*(*(p+j)+i)=*(*(p+0)+0)=*((a)+0)=a[0]=1

step2:i=0,j=1
*(*(p+i)+j)=*(*(p+0)+1)=*((a)+1)=a[1]=2
*(*(j+p)+i)=*(*(1+p)+0)=*((a+1)+0)=a[1]=2
*(*(i+p)+j)=*(*(p+0)+1)=*((a)+1)=a[1]=2
*(*(p+j)+i)=*(*(p+1)+0)=*((a+1)+0)=a[1]=2
step3:i=1,j=0
*(*(p+i)+j)=*(*(p+1)+0)=*((a+1)+0)=a[1]=2
*(*(j+p)+i)=*(*(p+0)+1)=*((a)+1)=a[1]=2
*(*(i+p)+j)=*(*(p+1)+0)=*((a+1)+0)=a[1]=2
*(*(p+j)+i)=*(*(p+0)+0)=*((a)+0)=a[1]=2
step4:i=1,j=1
*(*(p+i)+j)=*(*(p+1)+1)=*((a+1)+1)=a[2]=3
*(*(j+p)+i)=*(*(p+1)+1)=*((a+1)+1)=a[2]=3
*(*(i+p)+j)=*(*(p+1)+1)=*((a+1)+1)=a[2]=3
*(*(p+j)+i)=*(*(p+1)+1)=*((a+1)+1)=a[2]=3
(6)

Kim said:   1 decade ago
*p is an array of pointers each of wich is pointing to an element of the array a.

Lakshmi said:   1 decade ago
static int *p[] = {(int*)a, (int*)a+1, (int*)a+2};

Can you explain this step.

Peter said:   1 decade ago
Can you explain deeply.

Abin joseph said:   1 decade ago
Thank you Mr.Chand.
I like your explanation very much.
It is very helpfull.


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