View Compilation Error

0_0_31477504_23296.cpp: In function 'int main()':
0_0_31477504_23296.cpp:49:29: error: 'memset' was not declared in this scope
     memset(bit,0,sizeof(bit));
                             ^
0_0_31477504_23296.cpp:85:19: error: 'sort' was not declared in this scope
     sort(w+1,w+n+1);
                   ^