View Compilation Error

0_0_19230556_13793.cpp:34:18: error: 'rotl' function uses 'auto' type specifier without trailing return type
 auto rotl(Node *x) {auto y = x->r; x->r = y->l; y->l = x; x->upd(); y->upd(); return y;}
                  ^
0_0_19230556_13793.cpp:34:18: note: deduced return type only available with -std=c++1y or -std=gnu++1y
0_0_19230556_13793.cpp:35:18: error: 'rotr' function uses 'auto' type specifier without trailing return type
 auto rotr(Node *x) {auto y = x->l; x->l = y->r; y->r = x; x->upd(); y->upd(); return y;}
                  ^
0_0_19230556_13793.cpp:35:18: note: deduced return type only available with -std=c++1y or -std=gnu++1y
0_0_19230556_13793.cpp:81:9: error: expected initializer before '%' token
 void dfs%2
         ^