Language: C++

#include <iostream>
#include <cstdlib>

using namespace std

int main() {
  int N = 0;
  cin >> N;
  long long happy[N][3];
  cin >> happy[0] >> happy[1] >> happy[2];
  
  long long dp[N+1][3] = {0};
  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < 3; ++j) {
      for (int k = 0; j < 3; ++k) {
        if (j != k) {
          dp[i+1][k] = max(dp[i+1][k], dp[i][j] + happy[i][k]);
        }
      }
    }
  }
  
  long long result = 0;
  for (int i = 0; i < 3; ++i) {
    result = max(result, dp[N][j]);
  }
  cout << result << endl;
  
  return 0;
}

Compiler output:
a.cc:4:20: error: expected ';' before 'int'
    4 | using namespace std
      |                    ^
      |                    ;
    5 | 
    6 | int main() {
      | ~~~                 
a.cc: In function 'int main()':
a.cc:10:7: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'long long int [3]')
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |   ~~~ ^~ ~~~~~~~~
      |   |             |
      |   |             long long int [3]
      |   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:10:17: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'long long int*'
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
/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:10:17: error: invalid conversion from 'long long int*' to 'short int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(short int)((long long int*)(& happy[0]))' to 'short int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'short unsigned int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(short unsigned int)((long long int*)(& happy[0]))' to 'short unsigned int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(int)((long long int*)(& happy[0]))' to 'int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'unsigned int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(unsigned int)((long long int*)(& happy[0]))' to 'unsigned int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'long int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(long int)((long long int*)(& happy[0]))' to 'long int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'long unsigned int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(long unsigned int)((long long int*)(& happy[0]))' to 'long unsigned int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'long long int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(long long int)((long long int*)(& happy[0]))' to 'long long int&'
/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:10:17: error: invalid conversion from 'long long int*' to 'long long unsigned int' [-fpermissive]
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
      |                 |
      |                 long long int*
a.cc:10:17: error: cannot bind rvalue '(long long unsigned int)((long long int*)(& happy[0]))' to 'long long unsigned int&'
/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:10:17: error: cannot bind non-const lvalue reference of type 'void*&' to an rvalue of type 'void*'
   10 |   cin >> happy[0] >> happy[1] >> happy[2];
      |          ~~~~~~~^
/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>]'
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:25: note:   no known conversion for argument 1 from 'long long int [3]' to 'float&'
  219 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/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>]'
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:26: note:   no known conversion for argument 1 from 'long long int [3]' to 'double&'
  223 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/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>]'
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:31: note:   no known conversion for argument 1 from 'long long int [3]' to 'long double&'
  227 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/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>]'
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:36: note:   no known conversion for argument 1 from 'long long int [3]' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'}
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |