心得：做不出，補不動
HUD第一場：
1001 Blank Y
1002 Operation Y
1003 Milk
1004 Vication Y
1005 Path Y
1006 Typewriter
1007 Meteor
1008 Desert
1009 String
1010 Kingdom
1011 Function
1012 Sequence
1013 Code Y
HDU第二場：
1001 Another Chess Problem
1002 Beauty Of Unimodal Sequence Y
1003 Coefficient
1004 Double Tree
1005 Everything Is Generated In Equal Probability
1006 Fantastic Magic Cube
1007 Game
1008 Harmonious Army
1009 I Love Palindrome String ? 迴文樹
1010 Just Skip The Problem Y
1011 Keen On Everything But Triangle ? 線段樹
1012 Longest Subarray ?一個很好的題解，線段樹
HDU第三場:
1001 Azshara’s deep sea
1002 Blow up the city Y 支配樹
1003 Yukikaze and Demons
1004 Distribution of books Ｙ 二分＋DP + 線段樹/樹狀數組維護後綴最大值
1005 Easy Math Problem
1006 Fansblog Y
1007 Find the answer Y
1008 Game
1009 K Subsequence Y 費用流板子,但是我前向星建圖爆棧，換vector就可以了，玄學
1010 Sindar’s Art Exhibition
1011 Squrirrel
HDU第四場：
1001 AND Minimum Spanning Tree 31.75%(1018/3206) Y
1002 Colored Tree 0.00%(0/105)
1003 Divide the Stones 10.35%(126/1217) Y 注意n=1的情況
1004 Enveloping Convex 0.00%(0/125)
1005 Good Numbers 17.65%(9/51)
1006 Horse 29.03%(18/62)
1007 Just an Old Puzzle 31.83%(875/2749) Y
1008 K-th Closest Distance 10.97%(376/3429) ？線段樹＋二分
1009 Linear Functions 0.00%(0/35)
1010 Minimal Power of Prime 6.15%(328/5331) Y pow誤差真玄學貼一手博客
HDU第五場
1001 fraction 4.17%(7/168) Ｙ，輾轉相除法妙啊，有點像擴展歐幾里德
1002 three arrays 12.69%(76/599) Y 字典樹，妙啊
1003 geometric problem 1.59%(1/63)
1004 equation 20.65%(310/1501) Y 分Ｎ段處理，double不靠譜
1005 permutation 1 24.77%(407/1643) Y 連DFS都不會了，日益變菜
1006 string matching 23.12%(724/3131) Y 擴展KMP
1007 permutation 2 47.19%(688/1458)Y 貼一手自己博客
1008 line symmetric 1.87%(11/588) ？幾何腦闊通
1009 discrete logarithm problem 18.42%(7/38)
1010 find hidden array 6.25%(2/32)
HDU第六場
1001 Salty Fish 16.28%(7/43)
1002 Nonsense Time 7.88%(57/723)
1003 Milk Candy 12.90%(4/31)
1004 Speed Dog 26.97%(48/178)
1005 Snowy Smile 8.52%(225/2640) ?線段樹，最大子段和
1006 Faraway 27.92%(98/351) Y劃分平面，每個平面±60不影響答案，則直接統計
1007 Support or Not 8.33%(3/36)
1008 TDL 27.63%(921/3333) Y
1009 Three Investigators 7.14%(1/14)
1010 Ridiculous Netizens 38.71%(24/62)
1011 Dimensions 13.47%(64/475)
1012 Stay Real 45.04%(1044/2318) Y
HDU第七場
1001 A + B = C 10.52%(302/2872) ?模擬告辭
1002 Bracket Sequences on Tree 11.27%(16/142)
1003 Cuber Occurrence 6.67%(1/15)
1004 Data Structure Problem 23.08%(3/13)
1005 Equation 0.00%(0/63)
1006 Final Exam 5.06%(297/5872) Y貪心
1007 Getting Your Money Back 12.42%(20/161)
1008 Halt Hater 14.77%(61/413) ?直接打表找規律，並不想寫
1009 Intersection of Prisms 0.00%(0/2)
1010 Just Repeat 15.04%(128/851) Y很簡單的題目，比賽的時候沒做，補題用腳寫的代碼，心累
1011 Kejin Player 21.20%(544/2566) Y
HDU第八場
1001 Acesrc and Cube Hypernet 7.32%(3/41)
1002 Acesrc and Girlfriend 4.35%(2/46)
1003 Acesrc and Good Numbers 24.80%(213/859) Y
1004 Acesrc and Hunting 21.74%(90/414)
1005 Acesrc and String Theory 23.46%(38/162)
1006 Acesrc and Travel 12.01%(123/1024) ?換根DP
1007 Andy and Data Structure 0.85%(1/117)
1008 Andy and Maze 15.71%(33/210)
1009 Calabash and Landlord 18.99%(613/3228) Y
1010 Quailty and CCPC 33.48%(1060/3166) Y
1011 Roundgod and Milk Tea 17.70%(776/4384) Y
HDU多校第九場
1001 Rikka with Quicksort 25.85%(38/147)
1002 Rikka with Cake 31.69%(379/1196) Y，很經典的一個題目，平面上有n條水平或垂直的線段，求交點數量。 推薦博客
1003 Rikka with Mista 5.57%(45/808)
1004 Rikka with Geometric Sequence 9.52%(2/21)
1005 Rikka with Game 35.29%(866/2454) Y
1006 Rikka with Coin 7.16%(358/5003) Y，枚舉也需要貪心的呢
1007 Rikka with Travels 21.46%(85/396) Y,這個題目不錯，我好菜，計算那部分代碼是重點。
1008 Rikka with Stable Marriage 17.02%(8/47)
1009 Rikka with Traffic Light 0.00%(0/24)
1010 Rikka with Defensive Line 0.00%(0/20)
1011 Rikka with Segment Tree 39.39%(13/33)
HDU多校第10場
1001 Minimum Spanning Trees 22.22%(2/9)
1002 Line Graphs 11.11%(2/18)
1003 Valentine’s Day 18.66%(692/3709) ?證明看懵了
1004 Play Games with Rounddog 13.10%(11/84)
1005 Welcome Party 14.36%(497/3461) Y
1006 Dense Subgraph 20.83%(10/48)
1007 Closest Pair of Segments 3.21%(15/467)
1008 Coins 11.49%(87/757) Y，數據太大，暴力一點hdu抖動的有點恐怖。
1009 Block Breaker 55.41%(861/1554) Y
1010 Domino Covering 0.00%(0/11)
1011 Make Rounddog Happy 31.42%(126/401) ?推薦博客 啓發式分治，待補
2019CCPC秦皇島賽區（重現賽）
1001 Angle Beats 5.68%(58/1022) Y
1002 The Tree of Haruhi Suzumiya 50.00%(1/2)
1003 Sakurada Reset 0.00%(0/0)
1004 Decimal 42.92%(1012/2358) Y
1005 Escape 24.54%(53/216) Y網絡流，多分析，不然建圖都建不出
1006 Forest Program 10.76%(334/3105) Y
1007 Game on Chessboard 7.95%(7/88)
1008 Houraisan Kaguya 0.00%(0/71)
1009 Invoker 21.31%(322/1511) Y
1010 MUV LUV EXTRA 19.15%(348/1817) Y
1011 MUV LUV UNLIMITED 14.79%(54/365) Y
1012 MUV LUV ALTERNATIVE 25.00%(6/24)