My Public Problems Setting Collection

Here list some of the public problems set by me. Those extremely easy problems might not be included here.

Format: # ID / When / Problem Name / Where / Link / Difficulty / Comment

  1. September 2014 / 震波 / BZOJ 3730 / Luogu 6329 / ★★ / A centroid decomposition problem with range update and range query.
  2. June 2015 / Victor and Proposition / BestCoder Round #52 / HDU 5420 / ★★☆ / A SCC problem with persistent segment tree to make edges.
  3. December 2015 / 算术天才⑨与等差数列 / BZOJ 4373 / Luogu 5278 / ★★★ / Check whether the numbers in an interval can form an arithmetic sequence.
  4. January 2016 / Four / ICPCCamp 2016. Day 2. Zhejiang U Contest / QOJ 7203 / ★★★☆ / A scapegoat tree problem.
  5. March 2016 / C Language Practice / BZOJ 4454 / Luogu 5435 / ★★★★ / Calculate GCD in $O(1)$.
  6. May 2016 / Claris Loves Painting / "巴卡斯杯" 中国大学生程序设计竞赛 - 女生专场 / HDU 5709 BZOJ 4771 / ★★★ / A segment tree merge problem.
  7. July 2016 / Born Slippy / 2016 Multi-University Training Contest 2 / HDU 5735 / ★★★★ / Meet in the middle to maintain binary operations.
  8. July 2016 / Differencia / 2016 Multi-University Training Contest 2 / HDU 5737 / ★★★☆ / Precompute and store the merge sort to get rid of a $O(\log n)$ factor.
  9. August 2016 / Keep In Touch / BestCoder Round #86 / HDU 5807 / ★★★ / Speed up DP transition by another DP.
  10. August 2016 / Price List Strike Back / BestCoder Round #86 / HDU 5808 / ★★★☆ / A 0-1 Knapsack problem with 2D range query.
  11. September 2016 / Tree Cutting / BestCoder Round #88 / HDU 5909 / ★★☆ / Find the number of components on a tree such that the XOR sum of all vertices is $k$.
  12. September 2016 / Advanced Traffic System / BestCoder Round #88 / HDU 5910 / ★★★★☆ / Run Dijkstra cleverly to calculate the shortest path.
  13. December 2016 / 商店购物 / Lydsy2017省队十连测 / BZOJ 5215 / ★★ / Speed up principle of inclusion-exclusion by DP.
  14. December 2016 / 公路建设 / Lydsy2017省队十连测 / BZOJ 5216 / ★★ / An easy MST problem.
  15. December 2016 / 航海舰队 / Lydsy2017省队十连测 / BZOJ 5217 / ★★★☆ / Check whether a position can be reached by 2D FFT.
  16. December 2016 / 友好城市 / Lydsy2017省队十连测 / BZOJ 5218 / ★★★★ / Find SCC by Kosaraju with bitset, and find the edge set by sparse table.
  17. December 2016 / 最长路径 / Lydsy2017省队十连测 / BZOJ 5219 / ★★ / An easy tournament problem.
  18. December 2016 / 异或与区间加 / Lydsy2017省队十连测 / BZOJ 5220 / ★★★★ / A big-small problem.
  19. May 2017 / 天才黑客 / SDOI 2017 / Luogu 3783 / ★★★★ / An interesting shortest path problem.
  20. May 2017 / 切树游戏 / SDOI 2017 / Luogu 3781 / ★★★☆ / Dynamic tree DP with FWT.
  21. May 2017 / 文本校正 / SDOI 2017 / Luogu 3785 / ★★★★★ / A tough string theory problem.
  22. May 2017 / Forgiveness / 2017中国大学生程序设计竞赛 - 女生专场 / HDU 6028 / ★★★★☆ / Shift-And with lazy tag to do range update.
  23. June 2017 / 互质序列 / Lydsy1706月赛 / BZOJ 4921 / ★★☆ / A problem about the number of distinct values of range GCD is $O(n\log w)$.
  24. August 2017 / Big Integer / 2017 Multi-University Training Contest - Team 4 / HDU 6067 / ★★★☆ / A polynominal math problem.
  25. August 2017 / Classic Quotation / 2017 Multi-University Training Contest - Team 4 / HDU 6068 / ★★ / A KMP problem.
  26. August 2017 / Counting Divisors / 2017 Multi-University Training Contest - Team 4 / HDU 6069 / ★ / A sieve problem.
  27. August 2017 / Dirt Ratio / 2017 Multi-University Training Contest - Team 4 / HDU 6070 / ★★☆ / A binary search problem with segment tree.
  28. August 2017 / Lazy Running / 2017 Multi-University Training Contest - Team 4 / HDU 6071 / ★★★☆ / Find the shortest cycle with length at least $k$.
  29. August 2017 / Logical Chain / 2017 Multi-University Training Contest - Team 4 / HDU 6072 / ★★★★ / Find SCC by Kosaraju with bitset.
  30. August 2017 / Matching In Multiplication / 2017 Multi-University Training Contest - Team 4 / HDU 6073 / ★★☆ / An interesting graph problem.
  31. August 2017 / Phone Call / 2017 Multi-University Training Contest - Team 4 / HDU 6074 / ★★★ / Speed up Kruskal by DSU.
  32. August 2017 / Questionnaire / 2017 Multi-University Training Contest - Team 4 / HDU 6075 / ☆ / An easy constructive problem.
  33. August 2017 / Security Check / 2017 Multi-University Training Contest - Team 4 / HDU 6076 / ★★★ / A DP problem.
  34. August 2017 / Time To Get Up / 2017 Multi-University Training Contest - Team 4 / HDU 6077 / ☆ / An implemention problem.
  35. August 2017 / Wavel Sequence / 2017 Multi-University Training Contest - Team 4 / HDU 6078 / ★★★ / Count common wavel subsequence problem.
  36. August 2017 / Yuno And Claris / 2017 Multi-University Training Contest - Team 4 / HDU 6079 Luogu 4119 / ★★★★★ / The first problem of Ynoi Series.
  37. August 2017 / 小Q的方格纸 / Lydsy1708月赛 / BZOJ 4972 / ★ / Calculate the sum of a triangle range.
  38. August 2017 / 跳伞求生 / Lydsy1708月赛 / BZOJ 4977 / ★★★☆ / Hall with segment tree.
  39. August 2017 / 凌晨三点的宿舍 / Lydsy1708月赛 / BZOJ 4979 / ★★★★ / A divide & conquer problem.
  40. September 2017 / 塌陷的牧场 / Lydsy1709月赛 / BZOJ 5048 / ★★★ / Speed up brute-force by DSU.
  41. September 2017 / 建造摩天楼 / Lydsy1709月赛 / BZOJ 5050 / ★★★★ / A tough data structure problem.
  42. November 2017 / 实时导航 / Lydsy1711月赛 / BZOJ 5097 / ★★★☆ / Find shortest path in a graph when the weight of each edge is in $\{1,2,3,4\}$ by BFS & bitset.
  43. December 2017 / 线段树的匹配 / Lydsy1712月赛 / BZOJ 5123 / ★☆ / Find maximum matching in a huge segment tree.
  44. December 2017 / 小Q的书架 / Lydsy1712月赛 / BZOJ 5125 / ★★★☆ / Divide the sequence into $k$ intervals such that the total number of inversions in each part is minimized.
  45. December 2017 / 树上传送 / Lydsy1712月赛 / BZOJ 5129 / ★★★★ / Speed up Dijkstra by centroid decomposition.
  46. March 2018 / Minimal Subset Difference / VK Cup 2018 - Round 2 / CF 924 F / ★★★★☆ / A tough digit DP problem.
  47. May 2018 / 战略游戏 / SDOI 2018 / Luogu 4606 / ★★★ / Find the number of vertices such that the given $k$ vertices are not connected any more after removing that vertex.
  48. May 2018 / 原题识别 / SDOI 2018 / Luogu 4618 / ★★★★☆ / A tough data structure problem.
  49. May 2018 / 荣誉称号 / SDOI 2018 / Luogu 4620 / ★★☆ / An interesting tree DP problem.
  50. May 2018 / CCPC直播 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6297 / ☆ / An implemention problem.
  51. May 2018 / 口算训练 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6287 / ★☆ / An interesting math problem.
  52. May 2018 / 缺失的数据范围 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6288 / ★ / A binary search problem.
  53. May 2018 / 寻宝游戏 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6289 / ★★★★ / Find an optimal path with exchanging.
  54. May 2018 / 奢侈的旅行 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6290 / ★★☆ / An interesting shortest path problem.
  55. May 2018 / 对称数 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6291 / ★★★ / Find the smallest number on a chain of tree whose occurrence is even.
  56. May 2018 / quailty算法 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6293 / ★★★☆ / An interesting divide & conquer problem.
  57. May 2018 / 回文树 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6295 / ★ / Find the number of palindromic paths on a tree under random data.
  58. May 2018 / 代码派对 / "字节跳动杯"2018中国大学生程序设计竞赛-女生专场 / HDU 6296 / ★★★ / Find the number of triples $(i,j,k)$ such that rectangle $i,j,k$ has non-empty common area.
  59. May 2018 / 摘抄大赛 / Lydsy1805月赛 / BZOJ 5364 / ★★☆ / A tough implemention problem.
  60. June 2018 / 比例查询 / Lydsy1806月赛 / BZOJ 5389 / ★★☆ / Check whether there exists a pair $(i,j)$ such that $l\leq i,j\leq r$ and $\frac{a_i}{a_j}=k$.
  61. June 2018 / 最远点对 / Lydsy1806月赛 / BZOJ 5393 / ★★★★ / Range farthest pair of points problem under random data.
  62. June 2018 / Vertex Covers / 2018-2019 ACM-ICPC, China Multi-Provincial Collegiate Programming Contest / GYM 102222 K / ★★ / Count contributions among all vertex covers in a graph.
  63. June 2018 / Continuous Intervals / 2018-2019 ACM-ICPC, China Multi-Provincial Collegiate Programming Contest / GYM 102222 L / ★★☆ / Count the number of intervals $[l,r]$ such that after sorting the interval, the difference of any two neighbouring items is less than or equal to $1$.
  64. July 2018 / Ascending Rating / 2018 Multi-University Training Contest 3 / HDU 6319 / ★☆ / An interesting mono queue problem.
  65. July 2018 / Cut The String / 2018 Multi-University Training Contest 3 / HDU 6320 / ★★★★ / Count the number of ways to cut a substring into two parts such that each part is palindromic.
  66. July 2018 / Dynamic Graph Matching / 2018 Multi-University Training Contest 3 / HDU 6321 / ★★ / Count the number of matchings dynamically.
  67. July 2018 / Euler Function / 2018 Multi-University Training Contest 3 / HDU 6322 / ☆ / An easy interesting math problem.
  68. July 2018 / Find The Submatrix / 2018 Multi-University Training Contest 3 / HDU 6323 / ★★★☆ / Speed up DP by SMAWK.
  69. July 2018 / Grab The Tree / 2018 Multi-University Training Contest 3 / HDU 6324 / ☆ / An easy interesting game problem.
  70. July 2018 / Interstellar Travel / 2018 Multi-University Training Contest 3 / HDU 6325 / ★★ / A convex hull problem.
  71. July 2018 / Monster Hunter / 2018 Multi-University Training Contest 3 / HDU 6326 / ★★★★☆ / Find the best permutation to beat all monsters on a tree.
  72. July 2018 / Random Sequence / 2018 Multi-University Training Contest 3 / HDU 6327 / ★★☆ / Speed up DP by cut down the number of states.
  73. July 2018 / Rectangle Radar Scanner / 2018 Multi-University Training Contest 3 / HDU 6328 / ★★★★ / Answer rectangle range query in $O(n\log^2n)$ - $O(\log n)$.
  74. July 2018 / Transport Construction / 2018 Multi-University Training Contest 3 / HDU 6329 / ★★★★ / Find dot MST by Boruvka, divide & conquer and convex hull trick.
  75. July 2018 / Visual Cube / 2018 Multi-University Training Contest 3 / HDU 6330 / ★ / An implemention problem.
  76. July 2018 / Walking Plan / 2018 Multi-University Training Contest 3 / HDU 6331 / ★★★ / Find the shortest path from $u$ to $v$ with at least $k$ edges efficiently.
  77. October 2018 / Sequences Generator / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 B / ★★★★☆ / Make heavy-light decomposition on a string.
  78. October 2018 / Diameter of a Tree / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 D / ★★★☆ / Find the diameter of the tree by centroid decomposition and convex hull trick.
  79. October 2018 / The Kouga Ninja Scrolls / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 E / ★★ / Find the farthest pair of points in Manhattan distance with different colors.
  80. October 2018 / Counting Sheep in Ami Dongsuo / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 F / ★★★★ / Speed up DP by interpolation.
  81. October 2018 / Best ACMer Solves the Hardest Problem / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 G / ★☆ / Circle range query.
  82. October 2018 / How Much Memory Your Code Is Using? / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 J / ☆ / An implemention problem.
  83. October 2018 / Renaissance Past in Nancy / 2018-2019 ACM-ICPC, Asia Shenyang Regional Contest / GYM 101955 M / ★★★★☆ / Range Knapsack problem.
  84. October 2018 / Rikka with Minimum Spanning Trees / 2018-2019 ACM-ICPC, Asia Xuzhou Regional Contest / GYM 102012 A / ★ / A magic problem.
  85. October 2018 / Rikka with Subsequences / 2018-2019 ACM-ICPC, Asia Xuzhou Regional Contest / GYM 102012 D / ★★★ / A classical counting problem.
  86. October 2018 / Rikka with Intersections of Paths / 2018-2019 ACM-ICPC, Asia Xuzhou Regional Contest / GYM 102012 G / ★★★ / Count the number of ways to choose $k$ chains on a tree such that their intersection is non-empty.
  87. October 2018 / Rikka with A Long Colour Palette / 2018-2019 ACM-ICPC, Asia Xuzhou Regional Contest / GYM 102012 H / ★★ / Paint the intervals with $k$ colors such that the total length of the parts with all $k$ colors is maximized.
  88. October 2018 / Rikka with Sorting Networks / 2018-2019 ACM-ICPC, Asia Xuzhou Regional Contest / GYM 102012 I / ★☆ / Find the number of permutations such that after doing all the operations in the given sorting network, it becomes almost sorted.
  89. October 2018 / Rikka with Illuminations / 2018-2019 ACM-ICPC, Asia Xuzhou Regional Contest / GYM 102012 M / ★★☆ / Select minimum number of points to light the whole convex polygon.
  90. November 2018 / Supreme Command / 2018-2019 ACM-ICPC, Asia Jiaozuo Regional Contest / GYM 102028 C / ★★☆ / Speed up the implemention.
  91. November 2018 / Honeycomb / 2018-2019 ACM-ICPC, Asia Jiaozuo Regional Contest / GYM 102028 F / ★☆ / Find shortest path in honeycomb.
  92. November 2018 / Distance / 2018-2019 ACM-ICPC, Asia Jiaozuo Regional Contest / GYM 102028 I / ★ / An easy interesting greedy problem.
  93. November 2018 / Carpets Removal / 2018-2019 ACM-ICPC, Asia Jiaozuo Regional Contest / GYM 102028 J / ★★★★ / Remove two rectangles to minimize the union area of the remaining rectangles.
  94. November 2018 / Counting Failures on a Trie / 2018-2019 ACM-ICPC, Asia Jiaozuo Regional Contest / GYM 102028 K / ★★★☆ / Speed up walking down a Trie.
  95. December 2018 / Deja vu of … Go Players / 2018-2019 ACM-ICPC, Asia East Continent Finals / GYM 102056 D / ★ / An easy interesting game problem.
  96. January 2019 / Little Sub and Zuma / ZOJ Monthly, January 2019 / ZOJ 4088 / ★★★★★☆ / An interesting state-of-art Gauss Elimination problem.
  97. March 2019 / Square Graph / Moscow Pre-Finals Workshops 2019. Day 2. Grand Prix of China / QOJ 7088 / ★★★★ / A tough MST problem on a string.
  98. March 2019 / Three Dimensions / Moscow Pre-Finals Workshops 2019. Day 2. Grand Prix of China / QOJ 7089 / ★★★★☆ / A tough counting problem via digit DP.
  99. March 2019 / 艺术台阶 / “字节跳动杯” 杭州电子科技大学第十九届程序设计竞赛 / HDU 6472 / ★★★★ / An interesting calculus DP problem.
  100. March 2019 / Tiger Machine / “字节跳动杯” 杭州电子科技大学第十九届程序设计竞赛 / HDU 6474 / ★★☆ / An interesting analyzing problem.
  101. March 2019 / 商业竞争 / “字节跳动杯” 杭州电子科技大学第十九届程序设计竞赛 / HDU 6475 / ★★★☆ / 0-1 Knapsack problem with ternary search.
  102. March 2019 / 三色抽卡游戏 / “字节跳动杯” 杭州电子科技大学第十九届程序设计竞赛 / HDU 6478 / ★ / An easy interesting game problem.
  103. May 2019 / 世界地图 / SDOI 2019 / Luogu 5360 / ★★★★★ / Find MST in grid cells efficiently.
  104. May 2019 / Apple Business / The 13th Chinese Northeast Collegiate Programming Contest / GYM 102220 A / ★★★★ / Hall with tree DP.
  105. May 2019 / Balanced Diet / The 13th Chinese Northeast Collegiate Programming Contest / GYM 102220 B / ★ / An easy interesting greedy problem.
  106. May 2019 / Master of Data Structure / The 13th Chinese Northeast Collegiate Programming Contest / GYM 102220 D / ★★★ / A "fake" data structure problem.
  107. May 2019 / Mini-game Before Contest / The 13th Chinese Northeast Collegiate Programming Contest / GYM 102220 F / ★★☆ / Game on a graph.
  108. May 2019 / Radar Scanner / The 13th Chinese Northeast Collegiate Programming Contest / GYM 102220 G / ★☆ / An easy interesting greedy problem.
  109. May 2019 / Skyscraper / The 13th Chinese Northeast Collegiate Programming Contest / GYM 102220 H / ★★ / An easy data structure problem.
  110. August 2019 / Salty Fish / 2019 Multi-University Training Contest 6 / HDU 6634 / ★★★★ / An interesting minimum cut problem.
  111. August 2019 / Nonsense Time / 2019 Multi-University Training Contest 6 / HDU 6635 / ★★ / LIS problem with deletion under random data.
  112. August 2019 / Milk Candy / 2019 Multi-University Training Contest 6 / HDU 6636 / ★★★★ / A matroid intersection problem.
  113. August 2019 / Speed Dog / 2019 Multi-University Training Contest 6 / HDU 6637 / ★★★ / An LP duel problem.
  114. August 2019 / Snowy Smile / 2019 Multi-University Training Contest 6 / HDU 6638 / ★★ / Find the submatrix with maximum total weight in a sparse matrix.
  115. August 2019 / Faraway / 2019 Multi-University Training Contest 6 / HDU 6639 / ★☆ / An interesting math problem.
  116. August 2019 / Support or Not / 2019 Multi-University Training Contest 6 / HDU 6640 / ★★★★★ / Find the top $k$ closest pairs of spheres in 3D space.
  117. August 2019 / TDL / 2019 Multi-University Training Contest 6 / HDU 6641 / ★ / An easy interesting math problem.
  118. August 2019 / Three Investigators / 2019 Multi-University Training Contest 6 / HDU 6642 / ★★★★★ / Find $k$ disjoint non-decreasing subsequences with maximum total weight.
  119. August 2019 / Ridiculous Netizens / 2019 Multi-University Training Contest 6 / HDU 6643 / ★★★ / Count the number of components on a tree whose product is at most $k$.
  120. August 2019 / 11 Dimensions / 2019 Multi-University Training Contest 6 / HDU 6644 / ★★★☆ / A DAG decomposition problem.
  121. August 2019 / Stay Real / 2019 Multi-University Training Contest 6 / HDU 6645 / ★ / An easy interesting game problem.
  122. August 2019 / Game Prediction / Petrozavodsk Summer 2019. Day 1. Songyang Chen Contest 2 / QOJ 7589 / ★★★★ / A tough game problem under random data.
  123. October 2019 / Exchanging Gifts / The 2019 China Collegiate Programming Contest Harbin Site / GYM 102394 E / ★★ / Run Boyer-Moore majority vote algorithm by DP.
  124. October 2019 / Game Store / The 2019 China Collegiate Programming Contest Harbin Site / GYM 102394 G / ★★★★ / Maintain ternary basis dynamically with bitset.
  125. October 2019 / Highway Buses / The 2019 China Collegiate Programming Contest Harbin Site / GYM 102394 H / ★★★★☆ / Speed up Dijkstra by centroid decomposition on a connected graph with $n+50$ edges.
  126. October 2019 / Image Processing / The 2019 ICPC Asia Yinchuan Regional Contest / GYM 104021 C / ★★★★ / A tough DP speed up problem.
  127. October 2019 / Holes / The 2019 ICPC Asia Nanjing Regional Contest / GYM 103466 D / ★★★★★★ / A tough random walk problem.
  128. December 2019 / Incoming Asteroids / 2019-2020 ICPC Asia Hong Kong Regional Contest / GYM 102452 I / ★★★☆ / A "Half Alarm" problem.
  129. December 2019 / Key Project / 2019-2020 ICPC Asia Hong Kong Regional Contest / GYM 102452 K / ★★★☆ / A MCMF simulation problem.
  130. July 2020 / Total Eclipse / 2020 Multi-University Training Contest 2 / HDU 6763 / ★☆ / An easy graph problem.
  131. July 2020 / Blood Pressure Game / 2020 Multi-University Training Contest 2 / HDU 6764 / ★★★★ / A DP problem about permutation.
  132. July 2020 / Count on a Tree II Striking Back / 2020 Multi-University Training Contest 2 / HDU 6765 / ★★★★★ / Determine which tree chain contains more colors by estimation.
  133. July 2020 / Diamond Rush / 2020 Multi-University Training Contest 2 / HDU 6766 / ★★★★ / Find optimal path with a rectangle obstacle.
  134. July 2020 / New Equipments / 2020 Multi-University Training Contest 2 / HDU 6767 / ★☆ / Speed up MCMF by cutting down the size of the graph.
  135. July 2020 / The Oculus / 2020 Multi-University Training Contest 2 / HDU 6768 / ☆ / An easy hashing problem.
  136. July 2020 / In Search of Gold / 2020 Multi-University Training Contest 2 / HDU 6769 / ★★☆ / A tree DP problem with binary search.
  137. July 2020 / Dynamic Convex Hull / 2020 Multi-University Training Contest 2 / HDU 6770 / ★★★☆ / SMAWK with update.
  138. July 2020 / It's All Squares / 2020 Multi-University Training Contest 2 / HDU 6771 / ★★ / An easy interesting geometry problem.
  139. July 2020 / Lead of Wisdom / 2020 Multi-University Training Contest 2 / HDU 6772 / ★☆ / A branching problem.
  140. July 2020 / King of Hot Pot / 2020 Multi-University Training Contest 2 / HDU 6773 / ★★★★★☆ / Find optimal permutation to fetch optimal answers for $k=1,2,\dots,n$.
  141. July 2020 / String Distance / 2020 Multi-University Training Contest 2 / HDU 6774 / ★★ / An easy editing distance problem.
  142. July 2020 / Tokitsukaze and Rescue / 2020 Multi-University Training Contest 3 / HDU 6797 / ★★☆ / A branching problem under random data.
  143. October 2020 / Dividing the Points / The 17th Zhejiang Provincial Collegiate Programming Contest / GYM 102770 D / ★★★★ / A tough geometry problem.
  144. October 2020 / Just an Old Problem / The 17th Zhejiang Provincial Collegiate Programming Contest / GYM 102770 J / ★★★★★ / A tough mask DP problem on a graph.
  145. October 2020 / List of Products / The 17th Zhejiang Provincial Collegiate Programming Contest / GYM 102770 L / ★★★☆ / A random binary search problem.
  146. April 2021 / Restore Atlantis / The 18th Zhejiang Provincial Collegiate Programming Contest / GYM 103055 B / ★★★ / A data structure problem about union of rectangles.
  147. April 2021 / Shortest Path Query / The 18th Zhejiang Provincial Collegiate Programming Contest / GYM 103055 D / ★★★ / Find shortest path on a special graph.
  148. April 2021 / Specially Super Rare / The 18th Zhejiang Provincial Collegiate Programming Contest / GYM 103055 E / ★★★★☆ / Find longest palindromic subsequence in an almost palindromic string.
  149. April 2021 / String Freshman / The 18th Zhejiang Provincial Collegiate Programming Contest / GYM 103055 L / ☆ / An easy KMP problem.
  150. May 2021 / Maximize the Ratio / The 2020 ICPC Asia Yinchuan Regional Programming Contest / GYM 104022 F / ★★★☆ / Find optimal convex polygon with binary search.
  151. May 2021 / Tower of the Sorcerer / The 2020 ICPC Asia Yinchuan Regional Programming Contest / GYM 104022 M / ★★☆ / A DP speed up problem.
  152. May 2021 / Club Assignment / The 2020 ICPC Asia Macau Regional Contest / GYM 103119 C / ★★☆ / An interesting graph problem.
  153. May 2021 / Mountain / The 2020 ICPC Asia Macau Regional Contest / GYM 103119 E / ★★★ / A geometry problem.
  154. May 2021 / Nim Cheater / The 2020 ICPC Asia Macau Regional Contest / GYM 103119 I / ★★★☆ / Cut down memory usage by reordering operations and heavy-light decomposition.
  155. May 2021 / Jewel Grab / The 2020 ICPC Asia Macau Regional Contest / GYM 103119 J / ★★☆ / Speed up greedy algorithm by segment tree.
  156. May 2021 / Candy Ads / The 2020 ICPC Asia Macau Regional Contest / GYM 103119 K / ★★★★☆ / 2-SAT with bitset.
  157. July 2021 / Descent of Dragons / The 2020 ICPC Asia Shenyang Regional Programming Contest / GYM 103202 J / ★★★★★ / A tough data structure problem.
  158. July 2021 / Bookshop / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6973 / ★★★☆ / A tough data structure problem.
  159. July 2021 / Destinations / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6974 / ★★★★ / A duel problem.
  160. July 2021 / Forgiving Matching / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6975 / ★★ / A string problem with FFT.
  161. July 2021 / Game on Plane / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6976 / ★★ / An easy interesting game problem.
  162. July 2021 / Kart Race / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6977 / ★★★★★☆ / A tough plannar problem requiring lexicographically smallest LIS.
  163. July 2021 / New Equipments II / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6978 / ★★★★☆ / A tough MCMF problem.
  164. July 2021 / Photoshop Layers / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6979 / ☆ / An easy problem about Photoshop.
  165. July 2021 / Restore Atlantis II / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6980 / ★★★★★☆ / Range union of rectangles problem under random data.
  166. July 2021 / Rise in Price / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6981 / ★★★ / Speed up DP by kicking out non-optimal states.
  167. July 2021 / Road Discount / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6982 / ★★☆ / A classical MST problem.
  168. July 2021 / Segment Tree with Pruning / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6983 / ☆ / An easy problem about segment tree.
  169. July 2021 / Tree Planting / 2021“MINIEYE杯”中国大学生算法设计超级联赛（3） / HDU 6984 / ★★★★ / A tough mask DP problem with big small.
  170. October 2021 / 连锁商店 / 2021年中国大学生程序设计竞赛女生专场 / GYM 103389 C / ★★☆ / An interesting mask DP problem.
  171. October 2021 / 被遗忘的计划 / 2021年中国大学生程序设计竞赛女生专场 / GYM 103389 E / ★★★ / An interesting ad-hoc problem.
  172. October 2021 / 地图压缩 / 2021年中国大学生程序设计竞赛女生专场 / GYM 103389 F / ★★ / A 2D string peroid problem.
  173. October 2021 / 驾驶卡丁车 / 2021年中国大学生程序设计竞赛女生专场 / GYM 103389 I / ★ / An implemention problem.
  174. October 2021 / 最大权边独立集 / 2021年中国大学生程序设计竞赛女生专场 / GYM 103389 J / ★★☆ / A tree DP problem.
  175. November 2021 / Buy and Delete / The 2021 CCPC Guilin Onsite (XXII Open Cup, Grand Prix of EDG) / GYM 103409 E / ★☆ / An easy interesting graph problem.
  176. November 2021 / Popcount Words / The 2021 CCPC Guilin Onsite (XXII Open Cup, Grand Prix of EDG) / GYM 103409 H / ★★★★★☆ / Broadcast lazy tags on the Aho-Corasick automaton by digit DP.
  177. November 2021 / Tax / The 2021 CCPC Guilin Onsite (XXII Open Cup, Grand Prix of EDG) / GYM 103409 K / ★★☆ / Branch on the shortest path graph.
  178. November 2021 / Wiring Engineering / The 2021 CCPC Guilin Onsite (XXII Open Cup, Grand Prix of EDG) / GYM 103409 L / ★★★★★ / Find DP result with range query by divide & conquer.
  179. December 2021 / 魔塔 OL / CTT 2021 / UOJ 710 / ★★★★☆ / Beat monster with update & range query.
  180. April 2022 / The Profiteer / The 19th Zhejiang Provincial Collegiate Programming Contest / GYM 103687 D / ★★★★★★ / A magic divide & conquer problem to maintain Knapsack.
  181. April 2022 / Dynamic Reachability / The 19th Zhejiang Provincial Collegiate Programming Contest / GYM 103687 K / ★★★★★★☆ / Dynamic reachability on directed graph.
  182. July 2022 / New Equipments III / ByteDance-Moscow Workshops Camp 2022. The Final Contest / QOJ 4630 / ★★★★★★ / Find maximum-weight matching on a bipartite graph where the weight of each edge is in $\{1,2,3,4,5\}$.
  183. July 2022 / Equipment Upgrade / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7162 / ★★★ / A convolution math problem.
  184. July 2022 / Boss Rush / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7163 / ★★ / A mask DP problem with binary search.
  185. July 2022 / Cyber Language / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7164 / ☆ / An easy implemention problem.
  186. July 2022 / Divide the Sweets / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7165 / ★★★★★ / Speed up subset DP with convex hull trick.
  187. July 2022 / Spanning Tree Game / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7166 / ★★★★ / A tough MST problem.
  188. July 2022 / Dusk Moon / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7167 / ★★★☆ / Range minimum circle covering problem under random data.
  189. July 2022 / Shallow Moon / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7168 / ★★★★★ / A tough ad-hoc problem.
  190. July 2022 / Laser Alarm / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7169 / ★☆ / An easy geometry problem.
  191. July 2022 / Package Delivery / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7170 / ★ / An easy greedy problem.
  192. July 2022 / Range Reachability Query / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7171 / ★★★★☆ / Range reachability query on a DAG.
  193. July 2022 / Taxi / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7172 / ★★ / An interesting binary search problem.
  194. July 2022 / Two Permutations / 2022“杭电杯”中国大学生算法设计超级联赛（3） / HDU 7173 / ★ / An easy analyzing problem.
  195. December 2022 / No Bug No Game / The 2022 ICPC Asia Hangzhou Regional Programming Contest / GYM 104090 C / ★☆ / An easy DP problem.
  196. December 2022 / RPG Pro League / The 2022 ICPC Asia Hangzhou Regional Programming Contest / GYM 104090 H / ★★★★★ / Dynamic matroid with Hall.
  197. December 2022 / Painting / The 2022 ICPC Asia Hangzhou Regional Programming Contest / GYM 104090 J / ★★★★ / A geometry problem with binary lifting.
  198. December 2022 / Levenshtein Distance / The 2022 ICPC Asia Hangzhou Regional Programming Contest / GYM 104090 L / ★★★★★ / A tough problem about editing distance.
  199. January 2023 / Shortest Path Query / The 2023 ICPC Asia Hong Kong Regional Programming Contest (The 1st Universal Cup, Stage 2:Hong Kong) / GYM 104172 D / ★★★★☆ / Speed up DP by only keeping states on the border of the convex hull.
  200. January 2023 / Range Closest Pair of Points Query / The 2023 ICPC Asia Hong Kong Regional Programming Contest (The 1st Universal Cup, Stage 2:Hong Kong) / GYM 104172 I Luogu 9062 / ★★★★★★★ / Range closest pair of points query problem.
  201. April 2023 / Master of Polygon / The 1st Universal Cup. Stage 15: Hangzhou / QOJ 6403 / ★★★★★★★★ / Check whether the given segment intersects with the given simple polygon in $O(\log^2n)$.
  202. April 2023 / Shuttle Tour / The 1st Universal Cup. Stage 15: Hangzhou / QOJ 6404 / ★★☆ / A classical data structure problem.
  203. April 2023 / Stage Clear / The 1st Universal Cup. Stage 15: Hangzhou / QOJ 6406 / ★★★★☆ / Find the best permutation to beat all monsters on a DAG.
  204. July 2023 / Magma Cave / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7300 / ★★★☆ / Check whether there is a spanning tree whose $k$-th smallest edge's weight is $w$.
  205. July 2023 / King's Ruins / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7301 / ★★★★★ / 5D LIS Problem.
  206. July 2023 / Leshphon / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7302 / ★★★★ / Count the number of ways to delete exactly three edges such that the graph is not strongly connected anymore.
  207. July 2023 / Chaos Begin / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7303 / ★★ / An easy ad-hoc problem.
  208. July 2023 / Out of Control / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7304 / ★ / An easy DP problem.
  209. July 2023 / Dragon Seal / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7305 / ★★★★★ / Speed up tree DP by matroid intersection.
  210. July 2023 / Casino Royale / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7306 / ★★★★☆ / A tough DP problem.
  211. July 2023 / Teyberrs / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7307 / ★★★☆ / Speed up DP by segment tree.
  212. July 2023 / Operation Hope / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7308 / ★★ / A classical binary search problem.
  213. July 2023 / The Mine of Abyss / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7309 / ★★☆ / Range subset sum problem under random data.
  214. July 2023 / 8-bit Zoom / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7310 / ☆ / An easy implemention problem.
  215. July 2023 / Noblesse Code / 2023“钉耙编程”中国大学生算法设计超级联赛（3） / HDU 7311 / ★★ / Count on the Stern-Brocot Tree.
  216. August 2023 / Palindromic Beads / The 2023 CCPC Online Contest / GYM 104651 B / ★★★ / Find the longest palindromic subsequence on a tree with special constraint.
  217. August 2023 / Clique Challenge / The 2023 CCPC Online Contest / GYM 104651 C / ★★★★★ / Count the number of cliques in the given graph where $n,m\leq 1000$.
  218. August 2023 / Robot Experiment / The 2023 CCPC Online Contest / GYM 104651 E / ★ / An easy branching problem.
  219. August 2023 / Flying Ship Story / The 2023 CCPC Online Contest / GYM 104651 F / ★★★ / Find the pair $(x,y)$ with maximum value such that $x\neq a$ and $y\neq b$ in $O(1)$.
  220. August 2023 / Hurricane / The 2023 CCPC Online Contest / GYM 104651 H / ★★★☆ / Find all-pairs shortest paths in the complementary graph.
  221. August 2023 / Monster Generator / The 2023 CCPC Online Contest / GYM 104651 I / ★★★★ / Beat monsters every day.
  222. August 2023 / Find the Gap / The 2023 CCPC Online Contest / GYM 104651 J / ★★☆ / A geometry problem with corner cases.
  223. August 2023 / Sequence Shift / The 2023 CCPC Online Contest / GYM 104651 K / ★★★★ / $(\max, +)$ convolution under random data.
  224. August 2023 / Partially Free Meal / The 2023 CCPC Online Contest / GYM 104651 L / ★★★☆ / Speed up greedy by SMAWK.
  225. September 2023 / Multiply Then Plus / The 2023 ICPC Asia EC Regionals Online Contest (I) / GYM 104639 C / ★★★★★ / Convex hull trick with update and range query.
  226. September 2023 / Range Periodicity Query / The 2023 ICPC Asia EC Regionals Online Contest (I) / GYM 104639 H / ★★★ / A string period problem.
  227. October 2023 / Redundant Towers / 2023 China Collegiate Programming Contest (CCPC) Guilin Onsite / GYM 104768 F / ★★★★★★★☆ / Maintaining 
    cut-vertex by merging two graphs on a segment tree.
  228. October 2023 / Sweet Sugar / 2023 China Collegiate Programming Contest (CCPC) Guilin Onsite / GYM 104768 H / ★★★ / Find the maximum disjoint components on a tree such that the total weight of vertices in each component is exactly $k$.
  229. December 2023 / Festival Decorating / The 2023 ICPC Asia Hangzhou Regional Contest / GYM 104976 B / ★★★☆ / Find the smallest answer in convolution.
  230. December 2023 / Yet Another Shortest Path Query / The 2023 ICPC Asia Hangzhou Regional Contest / GYM 104976 C / ★★★★★★ / Find the shortest path on a planar graph such that the path contains no more than three edges.
  231. December 2023 / Top Cluster / The 2023 ICPC Asia Hangzhou Regional Contest / GYM 104976 F / ★★★ / A mex query problem on a tree.
  232. December 2023 / Snake Move / The 2023 ICPC Asia Hangzhou Regional Contest / GYM 104976 G / ★★ / An interesting snake game.
  233. December 2023 / Dreamy Putata / The 2023 ICPC Asia Hangzhou Regional Contest / GYM 104976 I / ★★★★★★ / A state-of-art dynamic Gauss Elimination problem.
  234. April 2024 / Team Arrangement / The 3rd Universal Cup. Stage 8: Cangqian / QOJ 8936 / ★★☆ / A branching and greedy problem.
  235. April 2024 / Crawling on a Tree / The 3rd Universal Cup. Stage 8: Cangqian / QOJ 8938 / ★★★★★★☆ / A tough DP problem requiring many observations.
  236. April 2024 / Even or Odd Spanning Tree / The 3rd Universal Cup. Stage 8: Cangqian / QOJ 8941 / ★★ / Finding the MST whose total weight is even/odd.
  237. July 2024 / 超维攻坚 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7469 / ★★ / A 3D geometry problem.
  238. July 2024 / 黑白边游戏 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7470 / ★★★★★ / Speed up DP by finding all unlabeled graphs.
  239. July 2024 / 最优 K 子段 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7471 / ★★ / Find prime length intervals under random data.
  240. July 2024 / 分组 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7472 / ★★★☆ / Divide $n$ items into $4$ groups in $O(2^n)$.
  241. July 2024 / 多层血条 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7473 / ☆ / An easy implemention problem.
  242. July 2024 / 延时操控 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7474 / ★★ / A classical DP problem.
  243. July 2024 / 序列更新 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7475 / ★★★ / An interesting Las Vegas algorithm.
  244. July 2024 / 魔法卡牌 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7476 / ★★★★★★ / A tough branching problem about SAT.
  245. July 2024 / 昵称检索 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7477 / ★ / An easy string problem with a little implemention.
  246. July 2024 / 矩阵的周期 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7478 / ★★★★★★ / A tough graph problem.
  247. July 2024 / 找环 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7479 / ★★★★☆ / A classical mean-cycle problem with persistent segment tree.
  248. July 2024 / 寻找宝藏 / 2024“钉耙编程”中国大学生算法设计超级联赛（4） / HDU 7480 / ★★★☆ / A sweeping line problem.
  249. September 2024 / Mountain Booking / The 2024 ICPC Asia EC Regionals Online Contest (II) / GYM 105358 B / ★★★★☆ / Group queries by virtual tree to answer all of them in one go.
  250. September 2024 / Points Selection / The 2024 ICPC Asia EC Regionals Online Contest (II) / GYM 105358 H / ★★★★ / 2-side modular subset sum problem under random data.
posted @ 2023-10-05 23:55  Claris  阅读(721)  评论(0)  编辑  收藏  举报