View Compilation Error

0_0_37830110_3412.cpp: In function 'void dfs(int, int)':
0_0_37830110_3412.cpp:21:14: error: expected unqualified-id before '[' token
     for(auto [a, b] : e[u])
              ^
0_0_37830110_3412.cpp:21:14: error: expected ';' before '[' token
0_0_37830110_3412.cpp:21:15: error: 'a' was not declared in this scope
     for(auto [a, b] : e[u])
               ^
0_0_37830110_3412.cpp:21:18: error: 'b' was not declared in this scope
     for(auto [a, b] : e[u])
                  ^
0_0_37830110_3412.cpp: In lambda function:
0_0_37830110_3412.cpp:21:21: error: expected '{' before ':' token
     for(auto [a, b] : e[u])
                     ^
0_0_37830110_3412.cpp: In function 'void dfs(int, int)':
0_0_37830110_3412.cpp:21:21: error: expected ';' before ':' token
0_0_37830110_3412.cpp:21:21: error: expected primary-expression before ':' token
0_0_37830110_3412.cpp:21:21: error: expected ')' before ':' token
0_0_37830110_3412.cpp:21:21: error: expected primary-expression before ':' token