Syntax not clear

#1

In Q7, please explain the sum equation, I mean why 2 pointers are used?

#2

@Enigmatctrance
The correct answer is C. Let’s dry run this code on an arr =

arr = [ 1 2 3 ]
[ 4 5 6 ]
[ 7 8 9 ]

At first iteration,
i = 0, sum = 0
sum = sum + *( *(arr+i) + i++ ) ;
sum = sum + *( *(arr+0) + 0 ) ; // i is 1 now because of i++ ;
sum = sum + *((arr[0]) + 0 ) ;
sum = sum + (arr[0][0] ) ;
sum = 0 + 1 ;
sum = 1 ;

At second iteration,
i = 1, sum = 1
sum = sum + *( *(arr+i) + i++ ) ;
sum = sum + *( *(arr+1) + 1 ) ; // i is 2 now because of i++ ;
sum = sum + *((arr[1]) + 1 ) ;
sum = sum + (arr[1][1] ) ;
sum = 1 + 5 ;
sum = 6 ;

At third iteration,
i = 2, sum = 6
sum = sum + *( *(arr+i) + i++ ) ;
sum = sum + *( *(arr+2) + 2 ) ; // i is 3 now because of i++ ;
sum = sum + *((arr[2]) + 2 ) ;
sum = sum + arr[2][2] ;
sum = 6 + 9 ;
sum = 15 ;

every time sum += arr[i][i] is happening and arr[i][i] is the diagonal element. Hence c option is the correct one.

Hope this helps :slight_smile:

#3

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