Solution

Solution of HNOI2008 “玩具装箱”(P3195)
dynamic programming with slope optimization & monotonous queue
Algorithms    Solution / HNOI / DP
Solution of Codeforces372 C
dynamic programming with monotonous stack
Algorithms    Solution / Codeforces / DP
Solution of USACO12OPEN G(P3067)
using the idea called "Meet in The Middle"
Algorithms    Solution / USACO