View Compilation Error

0_0_25037461_31375.cpp: In function 'int main()':
0_0_25037461_31375.cpp:10:29: error: 'memset' was not declared in this scope
         memset(a,0,sizeof(a));
                             ^
0_0_25037461_31375.cpp:17:19: error: 'sort' was not declared in this scope
     sort(a+1,a+1+n);
                   ^