View Compilation Error

0_0_29911826_17084.cpp: In function 'int main()':
0_0_29911826_17084.cpp:149:23: error: 'sort' was not declared in this scope
         sort(b+1,b+1+n);
                       ^
0_0_29911826_17084.cpp:150:28: error: 'unique' was not declared in this scope
         *b=unique(b+1,b+1+n)-b-1;
                            ^