답안 #733622

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
733622 2023-05-01T05:14:43 Z bin9638 철인 이종 경기 (APIO18_duathlon) C++17
컴파일 오류
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#include <bits/stdc++.h>

using namespace std;

#define N 200010
#define ll long long
#define fs first
#define sc second
#define ii pair<int,int>
#define pb push_back
#define int ll

int ans=0,times,num[N],low[N],n,m,ktr[N],dem,sz[N],child[N];
vector<int>g[N],edge[N];
stack<int>st;

void visit(int u,int p)
{
    num[u]=low[u]=++times;
    for(auto v:g[u])
        if(v!=p)
        {
            if(num[v]!=0)
            {
                low[u]=min(low[u],num[v]);
            }else
            {
                st.push(u);
                visit(v,u);
                low[u]=min(low[u],low[v]);
                if(low[v]>=num[u])
                {
                    int k;
                    dem++;
                    do{
                        k=st.top();
                        st.pop();

                        if(ktr[k]!=dem)
                        {
                             sz[dem]++;
                            ktr[k]=dem;
                            edge[dem].pb(k);
                            edge[k].pb(dem);
                        }
                    }while(k!=u);
                }
            }
        }
    st.push(u);
}

void build(int u,int p)
{
    child[u]=(u<=n);
    //cout<<u<<" "<<child[u]<<endl;
    for(auto v:edge[u])
        if(v!=p)
        {
            build(v,u);
            child[u]+=child[v];
        }
}

void DFS(int u,int p)
{
    if(u<=n)
    {
        int sum=n-1;
        for(auto v:edge[u])
            if(v!=p)
            {
                sum-=child[v];
                ans+=sum*child[v];
            //    cout<<sum<<" "<<child[v]<<endl;
            }
    }else
    {
        int sum=n;
        for(auto v:edge[u])
            if(v!=p)
            {
                sum-=child[v];
                ans+=sum*child[v]*(sz[u]-2);
               // cout<<u<<" "<<sum<<" "<<child[v]<<" "<<sz[u]<<endl;
            }
    }
    //cout<<u<<" "<<ans*2<<endl;
    for(auto v:edge[u])
        if(v!=p)
            DFS(v,u);
}

int32_t main()
{
  //  freopen("A.inp","r",stdin);
  //  freopen("A.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int u,v;
        cin>>u>>v;
        g[u].pb(v);
        g[v].pb(u);
    }
    dem=n;
    for(int i=1;i<=n;i++)
        if(num[i]==0)
            visit(i,0);
    //cout<<dem<<endl;
    build(1,0);
  // cout<<child[1]<<endl;
    DFS(1,0);
    cout<<ans*2;
    return 0;
}

Compilation message

In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant: In instantiation of 'constexpr decltype(auto) std::visit(_Visitor&&, _Variants&& ...) [with _Visitor = long long int&; _Variants = {int}]':
count_triplets.cpp:112:22:   required from here
/usr/include/c++/10/variant:1702:23: error: request for member 'valueless_by_exception' in '__variants#0', which is of non-class type 'int'
 1702 |       if ((__variants.valueless_by_exception() || ...))
      |            ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/variant:1706:22: error: no matching function for call to 'get<0>(int)'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/utility:223:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type& std::get(std::pair<_Tp1, _Tp2>&)'
  223 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/10/utility:223:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::pair<_Tp1, _Tp2>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/utility:228:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&& std::get(std::pair<_Tp1, _Tp2>&&)'
  228 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/10/utility:228:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::pair<_Tp1, _Tp2>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/utility:233:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr const typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type& std::get(const std::pair<_Tp1, _Tp2>&)'
  233 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/10/utility:233:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::pair<_Tp1, _Tp2>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/utility:238:5: note: candidate: 'template<long unsigned int _Int, class _Tp1, class _Tp2> constexpr const typename std::tuple_element<_Int, std::pair<_Tp1, _Tp2> >::type&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  238 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/10/utility:238:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::pair<_Tp1, _Tp2>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/utility:247:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp& std::get(std::pair<_T1, _T2>&)'
  247 |     get(pair<_Tp, _Up>& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:247:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:252:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp& std::get(const std::pair<_T1, _T2>&)'
  252 |     get(const pair<_Tp, _Up>& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:252:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:257:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp&& std::get(std::pair<_T1, _T2>&&)'
  257 |     get(pair<_Tp, _Up>&& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:257:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:262:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp&& std::get(const std::pair<_T1, _T2>&&)'
  262 |     get(const pair<_Tp, _Up>&& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:262:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:267:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp& std::get(std::pair<_Up, _Tp>&)'
  267 |     get(pair<_Up, _Tp>& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:267:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:272:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp& std::get(const std::pair<_Up, _Tp>&)'
  272 |     get(const pair<_Up, _Tp>& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:272:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:277:5: note: candidate: 'template<class _Tp, class _Up> constexpr _Tp&& std::get(std::pair<_Up, _Tp>&&)'
  277 |     get(pair<_Up, _Tp>&& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:277:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/utility:282:5: note: candidate: 'template<class _Tp, class _Up> constexpr const _Tp&& std::get(const std::pair<_Up, _Tp>&&)'
  282 |     get(const pair<_Up, _Tp>&& __p) noexcept
      |     ^~~
/usr/include/c++/10/utility:282:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/tuple:39,
                 from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/array:334:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr _Tp& std::get(std::array<_Tp, _Nm>&)'
  334 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/10/array:334:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::array<_Tp, _Nm>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/tuple:39,
                 from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/array:343:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr _Tp&& std::get(std::array<_Tp, _Nm>&&)'
  343 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/10/array:343:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::array<_Tp, _Nm>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/tuple:39,
                 from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/array:351:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr const _Tp& std::get(const std::array<_Tp, _Nm>&)'
  351 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/10/array:351:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::array<_Tp, _Nm>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/tuple:39,
                 from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/array:360:5: note: candidate: 'template<long unsigned int _Int, class _Tp, long unsigned int _Nm> constexpr const _Tp&& std::get(const std::array<_Tp, _Nm>&&)'
  360 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/10/array:360:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::array<_Tp, _Nm>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/tuple:1294:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_UTypes ...> >& std::get(std::tuple<_UTypes ...>&)'
 1294 |     get(tuple<_Elements...>& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1294:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::tuple<_UTypes ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/tuple:1300:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_UTypes ...> >& std::get(const std::tuple<_UTypes ...>&)'
 1300 |     get(const tuple<_Elements...>& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1300:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::tuple<_UTypes ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/tuple:1306:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_UTypes ...> >&& std::get(std::tuple<_UTypes ...>&&)'
 1306 |     get(tuple<_Elements...>&& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1306:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::tuple<_UTypes ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/tuple:1315:5: note: candidate: 'template<long unsigned int __i, class ... _Elements> constexpr std::__tuple_element_t<__i, std::tuple<_UTypes ...> >&& std::get(const std::tuple<_UTypes ...>&&)'
 1315 |     get(const tuple<_Elements...>&& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1315:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::tuple<_UTypes ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/functional:54,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from count_triplets.cpp:1:
/usr/include/c++/10/tuple:1338:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp& std::get(std::tuple<_UTypes ...>&)'
 1338 |     get(tuple<_Types...>& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1338:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/tuple:1344:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp&& std::get(std::tuple<_UTypes ...>&&)'
 1344 |     get(tuple<_Types...>&& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1344:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/tuple:1350:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr const _Tp& std::get(const std::tuple<_UTypes ...>&)'
 1350 |     get(const tuple<_Types...>& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1350:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/tuple:1357:5: note: candidate: 'template<class _Tp, class ... _Types> constexpr const _Tp&& std::get(const std::tuple<_UTypes ...>&&)'
 1357 |     get(const tuple<_Types...>&& __t) noexcept
      |     ^~~
/usr/include/c++/10/tuple:1357:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:133,
                 from count_triplets.cpp:1:
/usr/include/c++/10/variant:1644:5: note: candidate: 'template<long unsigned int _Np, class ... _Types> constexpr std::variant_alternative_t<_Np, std::variant<_Types ...> >& std::get(std::variant<_Types ...>&)'
 1644 |     get(variant<_Types...>& __v)
      |     ^~~
/usr/include/c++/10/variant:1644:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::variant<_Types ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/variant:1655:5: note: candidate: 'template<long unsigned int _Np, class ... _Types> constexpr std::variant_alternative_t<_Np, std::variant<_Types ...> >&& std::get(std::variant<_Types ...>&&)'
 1655 |     get(variant<_Types...>&& __v)
      |     ^~~
/usr/include/c++/10/variant:1655:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'std::variant<_Types ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/variant:1666:5: note: candidate: 'template<long unsigned int _Np, class ... _Types> constexpr std::variant_alternative_t<_Np, std::variant<_Types ...> >& std::get(const std::variant<_Types ...>&)'
 1666 |     get(const variant<_Types...>& __v)
      |     ^~~
/usr/include/c++/10/variant:1666:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::variant<_Types ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/variant:1677:5: note: candidate: 'template<long unsigned int _Np, class ... _Types> constexpr std::variant_alternative_t<_Np, std::variant<_Types ...> >&& std::get(const std::variant<_Types ...>&&)'
 1677 |     get(const variant<_Types...>&& __v)
      |     ^~~
/usr/include/c++/10/variant:1677:5: note:   template argument deduction/substitution failed:
/usr/include/c++/10/variant:1706:22: note:   mismatched types 'const std::variant<_Types ...>' and 'int'
 1706 |  decltype(std::get<0>(std::declval<_Variants>()))...>;
      |           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/variant:1071:20: note: candidate: 'template<class _Tp, class ... _Types> constexpr _Tp& std::get(std::variant<_Types ...>&)'
 1071