Language: C++

#include <iostream>
#include <algorithm>

#define INF 1e9

using namespace std;

int main() {
    int N, M, R;
    int r[9], G[201][201];

    for (int i = 0; i <= N; i++) {
        for (int j = 0; j <= N ; j++) {
            G[i][j] = (i == j) ? 0 : INF;
        }
    }

    cin >> N >> M >> R;

    for (int i = 0; i < R; i++) {
        cin >> r[i] - 1;
    }

    for (int i = 0; i < M; i++) {
        int A, B, C;
        cin >> A >> B >> C;
        G[A-1][B-1] = G[B-1][A-1] = C;
    }

    // Warshall–Floyd Algorithm
    for (int k = 0; k < N; k++) {
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                G[i][j] = min(G[i][j], G[i][k] + G[k][j]);
            }
        }
    }
 
    long long ans = INF;

    sort(r, r + R);

    do {
        long long t = 0;
        for (int i = 0; i < R-1; i++) {
            t += G[r[i]][r[i+1]];
        }
        ans = min(ans, t);
    } while (next_permutation(r, r + R));

    cout << ans << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:21:13: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'int')
   21 |         cin >> r[i] - 1;
      |         ~~~ ^~ ~~~~~~~~
      |         |           |
      |         |           int
      |         std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42,
                 from a.cc:1:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'short int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'short unsigned int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'unsigned int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'long int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'long unsigned int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'long long int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'long long unsigned int&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'float&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'double&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: cannot bind non-const lvalue reference of type 'long double&' to a value of type 'int'
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: invalid conversion from 'int' to 'void*' [-fpermissive]
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
      |                     |
      |                     int
a.cc:21:21: error: cannot bind rvalue '(void*)((long int)(r[i] - 1))' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: invalid conversion from 'int' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
      |                     |
      |                     int
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>; __ios_type = std::basic_ios<char>]' (near match)
  126 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:126:7: note:   conversion of argument 1 would be ill-formed:
a.cc:21:21: error: invalid conversion from 'int' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'} [-fpermissive]
   21 |         cin >> r[i] - 1;
      |                ~~~~~^~~
      |                     |
      |                     int
/usr/include/c++/14/istream:133:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  133 |