View Compilation Error

0_0_9356715_15505.cpp: In function `int main()':
0_0_9356715_15505.cpp:85: error: no match for 'operator[]' in 'hull[++cnt]'
0_0_9356715_15505.cpp:86: error: no match for 'operator[]' in 'hull[++cnt]'
0_0_9356715_15505.cpp:87: error: no match for 'operator[]' in 'hull[++cnt]'
0_0_9356715_15505.cpp:88: error: no match for 'operator[]' in 'hull[++cnt]'
0_0_9356715_15505.cpp:94: error: cannot convert `point_t' to `point_t*' for argument `1' to `int graham(point_t*, int)'
0_0_9356715_15505.cpp:96: error: cannot convert `point_t' to `point_t*' for argument `1' to `bool inside(point_t*, int, point_t)'