wqs二分/凸优化

- [CF125E MST Company](https://www.luogu.com.cn/problem/CF125E) - [P4983 忘情](https://www.luogu.com.cn/problem/P4983) - [P4767 [IOI2000]邮局](https://www.luogu.com.cn/problem/P4767) - [P4383 [八省联考2018]林克卡特树](https://www.luogu.com.cn/problem/P4383) - [CF321E Ciel and Gondolas](https://www.luogu.com.cn/problem/CF321E) - [CF739E Gosha is hunting](https://www.luogu.com.cn/problem/CF739E)