View Compilation Error

0_0_39005819_4230.cpp:17:1: error: 'vector' does not name a type
   17 | vector<point> p;
      | ^~~~~~
0_0_39005819_4230.cpp:22:1: error: 'vector' does not name a type
   22 | vector<point> res;
      | ^~~~~~
0_0_39005819_4230.cpp: In function 'int main()':
0_0_39005819_4230.cpp:32:13: error: 'p' was not declared in this scope
   32 |             p.push_back({x,y});
      |             ^
0_0_39005819_4230.cpp:34:14: error: 'p' was not declared in this scope
   34 |         sort(p.begin(),p.end(),cmp);
      |              ^
0_0_39005819_4230.cpp:38:23: error: 'p' was not declared in this scope
   38 |         while(tt>=2&&(p[stk[tt]]-p[stk[tt-1]])*(p[i]-p[stk[tt]])<=0)
      |                       ^
0_0_39005819_4230.cpp:46:29: error: 'p' was not declared in this scope
   46 |         while (tt > tmp && (p[stk[tt]] - p[stk[tt - 1]]) * (p[i] - p[stk[tt]]) <= 0)
      |                             ^