View Compilation Error

0_0_37688099_1480.cpp: In function 'void dfs(long long int, long long int)':
0_0_37688099_1480.cpp:35:9: error: expected unqualified-id before '[' token
     auto[a,b,c]=vec[u];
         ^
0_0_37688099_1480.cpp:36:7: error: 'a' was not declared in this scope
     f[a]--;
       ^
0_0_37688099_1480.cpp:37:7: error: 'b' was not declared in this scope
     f[b]--;
       ^
0_0_37688099_1480.cpp:38:7: error: 'c' was not declared in this scope
     f[c]--;
       ^