这题思路很简单，但是调试花了我一个下午……最后发现是一种情况没取 abs……（吐血）
题目链接：POJ 3977 Subset
✨ 全新设计的 Daydream 主题，强大的功能集成为你提供优雅的体验。欢迎使用。
POJ 3977 Subset 题解：折半搜索+二分查找
HDU 6447 YJJ's Salesman 题解：排序+离散+树状数组
Problem Description
YJJ is a salesman who has traveled through western country. YJJ is always on journey. Either is he at the destination, or on the way to destination.
One day, he is going to travel from city $A$ to southeastern city $B$. Let us assume that A is $(0,0)$ on the rectangle map and $B (10^9,10^9)$. YJJ is so busy so he never turn back or go twice the same way, he will only move to east, south or southeast, which means, if YJJ is at $(x,y)$ now $(0\leqslant x\leqslant 10^9,0\leqslant y\leqslant 10^9)$, he will only forward to $(x+1,y)$, $(x,y+1)$ or $(x+1,y+1)$.
HDU 5626 Clarke and points 题解：一道巧妙的贪心
斜率优化小结
在一维线性动态规划里，我们经常见到形如 $f(i)=min/max(f(j)+c_i)$（其实可以看成 $f(i)=min/max(a_i+b_j)$ ）这样形式的转移方程。朴素做法是 $\Theta (N^2)$。显然这样的形式可以用单调队列维护，优化到 $\Theta (N)$。但是如果遇到 $f(i)=min/max(a_i\ast b_j+c_i+d_j)$ 这样的，似乎用单调队列就难以维护了……因为 $a_i\ast b_j$ 既与 $i$ 有关，又与 $j$ 有关。这时候就要用到另一种优化方式：斜率优化。
Topcoder SRM 634 Div2 T3 SpecialStrings 题解
Topcoder Single Round Match 634 Div 2 T3 SpecialStrings 题解
Topcoder SRM 635 Div2 T3 LonglongestPathTree 题解
Topcoder Single Round Match 635 Div2 T3 LonglongestPathTree 题解
二分图匹配问题与匈牙利算法
Topcoder SRM 616 Div2 T3 TwoLLogo 题解
Topcoder Single Round Match 616 Div 2 T3 题解
Topcoder SRM 640 Div1 T1 ChristmasTreeDecoration 题解
Topcoder Single Round Match 640 Div 1 T1 ChristmasTreeDecoration 题解
别看了，这篇博客很水……
Topcoder SRM 637 Div2 T3 ConnectingGameDiv2 题解
Topcoder SIngle Round Match 637 Div 2 T3 ConnectingGameDiv2 题解