Language: C++

#include <algorithm>
#include <iostream>
#include <vector>
#include <set>

using namespace std;
constexpr long long MOD = 1000000007;

int main(void) {
    int N, M;
    set<int> a(100010,-1);
    vector<int> dp(100010,0);
    cin >> N >> M;
    for (int i=0;i<M;i++) {
        int q;
        cin >> q;
        a.insert(q);
    }

    dp[0] = 1; dp[1] = 1;
    for (int i=2;i<=N;i++) {
        if (a.find(i) != a.end()) continue;
        dp[i] = dp[i-2] + dp[i-1];
        if (a.find(i-2) != a.end()) dp[i] -= dp[i-2];
        if (a.find(i-1) != a.end()) dp[i] -= dp[i-1];
        dp[i] %= MOD;
    }
    cout << dp[N] << endl;

    return 0;
}

Compiler output:
In file included from /usr/include/c++/14/set:63,
                 from a.cc:4:
/usr/include/c++/14/bits/stl_set.h: In instantiation of 'std::set<_Key, _Compare, _Alloc>::set(_InputIterator, _InputIterator) [with _InputIterator = int; _Key = int; _Compare = std::less<int>; _Alloc = std::allocator<int>]':
a.cc:11:25:   required from here
   11 |     set<int> a(100010,-1);
      |                         ^
/usr/include/c++/14/bits/stl_set.h:195:38: error: no matching function for call to 'std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::_M_insert_range_unique(int&, int&)'
  195 |         { _M_t._M_insert_range_unique(__first, __last); }
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/set:62:
/usr/include/c++/14/bits/stl_tree.h:1096:9: note: candidate: 'template<class _InputIterator> std::__enable_if_t<((bool)std::is_same<_Val, typename std::iterator_traits<_InputIterator>::value_type>::value)> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_range_unique(_InputIterator, _InputIterator) [with _Key = int; _Val = int; _KeyOfValue = std::_Identity<int>; _Compare = std::less<int>; _Alloc = std::allocator<int>]'
 1096 |         _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
      |         ^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:1096:9: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_tree.h: In substitution of 'template<class _InputIterator> std::__enable_if_t<((bool)std::is_same<int, typename std::iterator_traits< <template-parameter-1-1> >::value_type>::value), void> std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::_M_insert_range_unique(_InputIterator, _InputIterator) [with _InputIterator = int]':
/usr/include/c++/14/bits/stl_set.h:195:31:   required from 'std::set<_Key, _Compare, _Alloc>::set(_InputIterator, _InputIterator) [with _InputIterator = int; _Key = int; _Compare = std::less<int>; _Alloc = std::allocator<int>]'
  195 |         { _M_t._M_insert_range_unique(__first, __last); }
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
a.cc:11:25:   required from here
   11 |     set<int> a(100010,-1);
      |                         ^
/usr/include/c++/14/bits/stl_tree.h:1095:58: error: no type named 'value_type' in 'struct std::iterator_traits<int>'
 1095 |         __enable_if_t<__same_value_type<_InputIterator>::value>
      |                                                          ^~~~~
/usr/include/c++/14/bits/stl_set.h: In instantiation of 'std::set<_Key, _Compare, _Alloc>::set(_InputIterator, _InputIterator) [with _InputIterator = int; _Key = int; _Compare = std::less<int>; _Alloc = std::allocator<int>]':
a.cc:11:25:   required from here
   11 |     set<int> a(100010,-1);
      |                         ^
/usr/include/c++/14/bits/stl_tree.h:1105:9: note: candidate: 'template<class _InputIterator> std::__enable_if_t<((bool)(! std::is_same<_Val, typename std::iterator_traits<_InputIterator>::value_type>::value))> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_range_unique(_InputIterator, _InputIterator) [with _Key = int; _Val = int; _KeyOfValue = std::_Identity<int>; _Compare = std::less<int>; _Alloc = std::allocator<int>]'
 1105 |         _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
      |         ^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:1105:9: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_tree.h: In substitution of 'template<class _InputIterator> std::__enable_if_t<((bool)(! std::is_same<int, typename std::iterator_traits< <template-parameter-1-1> >::value_type>::value)), void> std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>, std::allocator<int> >::_M_insert_range_unique(_InputIterator, _InputIterator) [with _InputIterator = int]':
/usr/include/c++/14/bits/stl_set.h:195:31:   required from 'std::set<_Key, _Compare, _Alloc>::set(_InputIterator, _InputIterator) [with _InputIterator = int; _Key = int; _Compare = std::less<int>; _Alloc = std::allocator<int>]'
  195 |         { _M_t._M_insert_range_unique(__first, __last); }
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
a.cc:11:25:   required from here
   11 |     set<int> a(100010,-1);
      |                         ^
/usr/include/c++/14/bits/stl_tree.h:1104:59: error: no type named 'value_type' in 'struct std::iterator_traits<int>'
 1104 |         __enable_if_t<!__same_value_type<_InputIterator>::value>
      |                                                           ^~~~~