View Compilation Error

0_0_37953423_19706.cpp: In function 'void solve()':
0_0_37953423_19706.cpp:78:14: error: expected unqualified-id before '[' token
         auto [val, x] = q.top();
              ^
0_0_37953423_19706.cpp:79:13: error: 'val' was not declared in this scope
         if (val == 0)
             ^
0_0_37953423_19706.cpp:81:19: error: 'x' was not declared in this scope
             ans = x;
                   ^
0_0_37953423_19706.cpp:88:26: error: 'x' was not declared in this scope
                 auto y = x + (char)(i + '0');
                          ^