Why are we swapping the same indices?

#1

In the function partition’s FOR loop, we are swapping if the array[j] < pivot.
But if you do dry run, the indices to be swapped will ALWAYS BE the same. So there is no use of swapping.
I have removed the swapping and even then the program is working fine in all cases.
Can you explain to me why do we need to swap inside the for loop?

#2

@rahulrana1998
we are not swapping the same indices every time we swap some indices we increase the value of i swapping is the key part of the quicksort algorithm which brings all lesser element to the left side we can not skip it
int arr[] = {10, 7, 8, 9, 1, 5};
try this without swapping it will not work
if you still have a dout feel free to ask

#3

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