Question

Is there is a easy way to make next_permutation to perform same set of swaps two different arrays of same size
for example
if i have two arrays a[]={1,2,3,4,5} and b[]={12,23,21,2,3}
if after permution 1 in array a goes to 3rd position then 12 in array b should also go to 3rd position.

Answer 1

You can make an auxiliary index set:

int a[] = { 1, 2, 3, 4, 5 };
int b[] = { 12, 23, 21, 2, 3 };

std::size_t indices[] = { 0, 1, 2, 3, 4 };

Now perform the permutations on indices, and then use a[indices[i]] and b[indices[i]].