View Compilation Error

0_0_22147516_17135.cpp: In function 'int main()':
0_0_22147516_17135.cpp:36:27: error: 'memset' was not declared in this scope
   memset(b,false,sizeof(b));
                           ^
0_0_22147516_17135.cpp:42:21: error: 'sort' was not declared in this scope
   sort(a, a+n+1, cmp);
                     ^