View Compilation Error

0_0_15352181_27138.cpp: In function 'double cal(int, int)':
0_0_15352181_27138.cpp:54:25: error: 'sort' was not declared in this scope
     sort(temp,temp+k,cmp);
                         ^
0_0_15352181_27138.cpp: In function 'int main()':
0_0_15352181_27138.cpp:74:38: error: 'sort' was not declared in this scope
             sort(point,point+Case,cmp);
                                      ^