next_permutation()

[vrakas]

Hello. I want to use next permutation on an array of structs i did depending on an integer variable x. Can i do this?

struct my_struct{
int x;
....
};

[LB]

I don't understand what exactly it is you want, can you try explaining it more?

[vrakas]

lets say i have a struct s

struct s
{
int a,b;
}

and

s arr[3];
arr[0].a=1;
arr[0].b=1;
arr[1].a=2;
arr[0].b=1;
arr[2].a=3;
arr[0].b=1;

i want to do next permutation depending on the int a. (there are6 permutations here).
can i do it?

[JLBorges]

#include <vector>

int main()
{
    struct S { S( int a, int b ) : a(a), b(b) {} int a, b ; } ;

    std::vector<S> seq ;

    for( int a : { 1, 2, 3 } ) for( int b : { 4, 5 } ) seq.emplace_back( a, b ) ;
}

[AbstractionAnon]

Yes, however you need a custom comparison function to determine which of two instances of the struct should be ordered first.
http://www.cplusplus.com/reference/algorithm/next_permutation/?kw=next_permutation