View Compilation Error

0_0_22849062_13460.cpp: In function 'int sg(bits)':
0_0_22849062_13460.cpp:35:5: error: 'u_long' was not declared in this scope
     u_long state_num = state.to_ulong();
     ^
0_0_22849062_13460.cpp:36:13: error: 'state_num' was not declared in this scope
     if (vis[state_num]) return SG[state_num];
             ^
0_0_22849062_13460.cpp:37:9: error: 'state_num' was not declared in this scope
     vis[state_num] = true;
         ^