View Compilation Error

0_0_26985865_1051.cpp:1:9: error: expected unqualified-id before 'for'
         for (int i = 1; i <= (1 << n); ++i) {
         ^
0_0_26985865_1051.cpp:1:25: error: 'i' does not name a type
         for (int i = 1; i <= (1 << n); ++i) {
                         ^
0_0_26985865_1051.cpp:1:40: error: expected unqualified-id before '++' token
         for (int i = 1; i <= (1 << n); ++i) {
                                        ^