View Compilation Error

0_0_28703389_1136.cpp: In function 'int main()':
0_0_28703389_1136.cpp:42:33: error: 'memset' was not declared in this scope
         memset(num,0,sizeof(num));
                                 ^
0_0_28703389_1136.cpp:51:27: error: 'sort' was not declared in this scope
         sort(q+1,q+1+m,cmp);
                           ^