Language: C++

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <functional>
#include <map>
#include <set>
#include <cstring>
#include <string>
#include <cctype>
#include <cassert>

using namespace std;

#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i = 0; i < (n); i++)
#define repr(i,b,e) for(int i = (b); i <= (e); i++)
#define INF (1001001001)
#define EPS (1e-15)

#define pr(x) do{cout << (#x) << " = " << (x) << endl;}while(0)
#define pri(x,i) do{cout << (#x) << "[" << i << "] = " << (x[i]) << endl;}while(0)
#define pra(x,n) rep(__i,n) pri(x,__i);
#define prar(x,b,e) repr(__i,b,e) pri(x,__i);

typedef long long ll;
typedef pair<int, int> pint;
typedef vector<int> vint;

int in() {
	int a;
	scanf("%d ", &a);
	return a;
}

int main() {
	int N = in();
	vint a(N+1), b(N+1);
	int hoge = 0, fuga = 0;
	rep(i,N) hoge ^= a[i] = in();
	rep(i,N) fuga ^= b[i] = in();
	a[N] = hoge, b[N] = fuga;
	vint c = a, d = b;
	sort(c.begin(), c.end());
	sort(d.begin(), d.end());
	rep(i,N+1) {
		if (c[i] != d[i]) {
			cout << -1 << endl;
			return 0;
		}
	}
	
	map<int, vint*> data;
	int siz = 0;
	set<int> ind;
	rep(i,N) {
		if (a[i] == b[i]) continue;
		ind.insert(i);
		if (data.find(b[i]) == data.end()) {
			data[b[i]] = new vint(1,i);
		}
		else {
			data[b[i]]->pb(i);
		}
		siz++;
	}
	int ans = 0;
	int t = a[N];
	for (; siz > 0;) {
		ans++;
		vint *v = data[t];
		if (v && v->size() > 0) {
			int j = v->at(v->size() - 1);
			v->pop_back();
			ind.erase(j);
			int temp = a[j];
			a[j] = t;
			t = temp;
			siz--;
		}
		else {
			int j = *(ind.begin());
			for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
				if (a[*i] == t) continue;
				j = *i;
				if (a[j] != b[N]) break;
			}
			int temp = a[j];
			a[j] = t;
			t = temp;
		}
	}
	cout << ans << endl;
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:87:63: error: conversion from 'std::set<int>::reverse_iterator' {aka 'std::reverse_iterator<std::_Rb_tree_const_iterator<int> >'} to non-scalar type 'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} requested
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                     ~~~~~~~~~~^~
a.cc:87:69: error: no match for 'operator!=' (operand types are 'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} and 'std::set<int>::reverse_iterator' {aka 'std::reverse_iterator<std::_Rb_tree_const_iterator<int> >'})
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                   ~ ^~ ~~~~~~~~~~
      |                                                                   |            |
      |                                                                   |            std::set<int>::reverse_iterator {aka std::reverse_iterator<std::_Rb_tree_const_iterator<int> >}
      |                                                                   std::set<int>::iterator {aka std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator}
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/bits/specfun.h:43,
                 from /usr/include/c++/14/cmath:3906,
                 from a.cc:3:
/usr/include/c++/14/bits/stl_pair.h:1052:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator!=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1052 |     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1052:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::pair<_T1, _T2>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:455:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  455 |     operator!=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:455:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::reverse_iterator<_Iterator>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
/usr/include/c++/14/bits/stl_iterator.h:500:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  500 |     operator!=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::reverse_iterator<_Iterator>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1686 |     operator!=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::move_iterator<_IteratorL>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1753 |     operator!=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::move_iterator<_IteratorL>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:4:
/usr/include/c++/14/bits/postypes.h:197:5: note: candidate: 'template<class _StateT> bool std::operator!=(const fpos<_StateT>&, const fpos<_StateT>&)'
  197 |     operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:197:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::fpos<_StateT>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
In file included from /usr/include/c++/14/string:43,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/bits/allocator.h:243:5: note: candidate: 'template<class _T1, class _T2> bool std::operator!=(const allocator<_CharT>&, const allocator<_T2>&)'
  243 |     operator!=(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:243:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::set<int>::iterator' {aka 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::const_iterator'} is not derived from 'const std::allocator<_CharT>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:651:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  651 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:651:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::_Rb_tree_const_iterator<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
/usr/include/c++/14/string_view:658:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  658 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:658:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::_Rb_tree_const_iterator<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
/usr/include/c++/14/string_view:666:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  666 |     operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:666:5: note:   template argument deduction/substitution failed:
a.cc:87:81: note:   'std::reverse_iterator<std::_Rb_tree_const_iterator<int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   87 |                         for (set<int>::iterator i = ind.rbegin(); i != ind.rend(); ++i) {
      |                                                                                 ^
/usr/include/c++/14/bits/basic_string.h:3833:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3833 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/