View Compilation Error

0_0_23536603_11889.cpp: In function 'int main()':
0_0_23536603_11889.cpp:193:23: error: 'sort' was not declared in this scope
         sort(poi,poi+n);
                       ^
0_0_23536603_11889.cpp:194:27: error: 'unique' was not declared in this scope
         n=unique(poi,poi+n)-poi;
                           ^