View Compilation Error

0_0_21650800_17245.cpp:42:9: error: 'bitset' does not name a type
 typedef bitset<32> bs;
         ^
0_0_21650800_17245.cpp:50:13: error: variable or field 'insert' declared void
 void insert(bs a){
             ^
0_0_21650800_17245.cpp:50:13: error: 'bs' was not declared in this scope