View Compilation Error

0_0_33837364_11442.cpp: In function 'int main()':
0_0_33837364_11442.cpp:11:12: error: unable to find numeric literal operator 'operator""f'
       f[i]=3f[i-1]+2;
            ^
0_0_33837364_11442.cpp:11:12: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes