View Compilation Error

0_0_24393414_7772.cpp: In function 'll countt(int*, int, int, bool)':
0_0_24393414_7772.cpp:30:30: error: unable to find numeric literal operator 'operator""i'
    ans += countt(sw,w-1,0,bj&7i==e);
                              ^
0_0_24393414_7772.cpp:30:30: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes