第二份代码第25行，括号匹配错了
by chengcheng567 @ 2023-07-12 15:22:56
(y(q[r])-y(q[r-1])*(x(i)-x(q[r])))
改成(y(q[r])-y(q[r-1]))*(x(i)-x(q[r]))
by chengcheng567 @ 2023-07-12 15:24:16
```cpp
while(l<r and (y(q[r])-y(q[r-1])*(x(i)-x(q[r])))>=(y(i)-y(q[r]))*(x(q[r])-x(q[r-1])))r--;
```
```cpp
while(l<r and (y(q[r])-y(q[r-1]))*(x(i)-x(q[r]))>=(y(i)-y(q[r]))*(x(q[r])-x(q[r-1])))r--;
```
by Gypsophila @ 2023-07-12 15:27:57
@[Gypsophila](/user/54745) @[chengcheng567](/user/371898) thx
（回的有点晚）
by SnowTrace @ 2023-07-15 10:16:23