Data Structure:
1.447 DIV2 D
http://codeforces.com/contest/447/problem/D
2.447 DIV2 E
http://codeforces.com/contest/447/problem/E
Math:
1.450 DIV2 E
http://codeforces.com/contest/450/problem/E
2.451 DIV2 D
http://codeforces.com/contest/451/problem/D
3.451 DIV2 E Number theory, generating function
http://codeforces.com/contest/451/problem/E
4.UVA 11761 Super Heronian Triangle 中学数学
http://vjudge.net/contest/view.action?cid=50801#problem/A
Graph theory:
1.ZOJ 3232 It's not Floyd Algorithm 强连通+floyd
http://vjudge.net/contest/view.action?cid=51135#problem/B
Computational geometry:
1.ZOJ 3234 Protect the King 凸包
http://vjudge.net/contest/view.action?cid=51135
Dynamic programming:
1.UVA 11766 Racing Car Computer 有点乱的dp?
http://vjudge.net/contest/view.action?cid=50801#problem/F
杂题:
1.UVA 11768 Lattice Point or Not 一点数学+机智
http://vjudge.net/contest/view.action?cid=50801#problem/H