library cheker(yosupo judge)のユニークAC者数を調べてみました

[library checker](https://judge.yosupo.jp/)を埋めようと思ったときにどこから手を付けるべきかわからなかったので難易度表代わりとして。
※2021/06/13夜時点の集計。ACしたユニークユーザの数をカウント、(Anonymous)は除外です。


| rank | Problem                                             | User |
| ---- | --------------------------------------------------- | ---- |
| 1    | A + B                                               | 583  |
| 2    | Unionfind                                           | 546  |
| 3    | Many A + B                                          | 496  |
| 4    | Static RMQ                                          | 464  |
| 5    | Static Range Sum                                    | 454  |
| 6    | Point Add Range Sum                                 | 430  |
| 7    | Associative Array                                   | 390  |
| 8    | Point Set Range  Composite                          | 267  |
| 9    | Lowest Common  Ancestor                             | 267  |
| 10   | Range Affine Range  Sum                             | 230  |
| 11   | Convolution                                         | 224  |
| 12   | Z Algorithm                                         | 205  |
| 13   | Suffix Array                                        | 196  |
| 14   | Strongly Connected  Components                      | 182  |
| 15   | Shortest Path                                       | 178  |
| 16   | Vertex Add Path Sum                                 | 149  |
| 17   | Convolution (mod  1,000,000,007)                    | 139  |
| 18   | Inv of Formal Power  Series                         | 135  |
| 19   | Range Kth Smallest                                  | 133  |
| 20   | Tree Diameter                                       | 131  |
| 21   | Matching on Bipartite  Graph                        | 128  |
| 22   | Vertex Add Subtree  Sum                             | 120  |
| 23   | Determinant of Matrix                               | 116  |
| 24   | Number of Substrings                                | 111  |
| 25   | Line Add Get Min                                    | 106  |
| 26   | Exp of Formal Power  Series                         | 101  |
| 27   | Log of Formal Power  Series                         | 100  |
| 28   | Factorize                                           | 99   |
| 29   | Queue Operate All  Composite                        | 97   |
| 30   | Sort Points by  Argument                            | 95   |
| 31   | Range Chmin Chmax Add  Range Sum                    | 93   |
| 32   | Two-Edge-Connected  Components                      | 91   |
| 33   | Set Xor-Min                                         | 89   |
| 34   | 2 Sat                                               | 89   |
| 35   | Vertex Set Path  Composite                          | 82   |
| 36   | Pow of Formal Power  Series                         | 78   |
| 37   | Sqrt Mod                                            | 77   |
| 38   | Enumerate Primes                                    | 76   |
| 39   | Cycle Detection                                     | 75   |
| 40   | Segment Add Get Min                                 | 73   |
| 41   | Counting Primes                                     | 72   |
| 42   | Subset Convolution                                  | 71   |
| 43   | Multipoint Evaluation                               | 70   |
| 44   | Sum of Floor of  Linear                             | 70   |
| 45   | Discrete Logarithm                                  | 69   |
| 46   | Persistent UnionFind                                | 67   |
| 47   | Maximum Independent  Set                            | 66   |
| 48   | Rectangle Sum                                       | 62   |
| 49   | Static Range  Inversions Query                      | 61   |
| 50   | Sqrt of Formal Power  Series                        | 55   |
| 51   | Montmort Number                                     | 53   |
| 52   | Find Linear  Recurrence                             | 53   |
| 53   | Dynamic Tree Vertex  Add Path Sum                   | 53   |
| 54   | Assignment Problem                                  | 52   |
| 55   | Persistent Queue                                    | 52   |
| 56   | Point Add Rectangle  Sum                            | 51   |
| 57   | Bitwise Xor  Convolution                            | 50   |
| 58   | Bitwise And  Convolution                            | 49   |
| 59   | Polynomial  Interpolation                           | 46   |
| 60   | Kth Root(Integer)                                   | 45   |
| 61   | Partition Function                                  | 44   |
| 62   | Matching on General  Graph                          | 43   |
| 63   | Stirling Number of  the First Kind                  | 42   |
| 64   | $\#_p$ Subset Sum                                   | 41   |
| 65   | Cartesian Tree                                      | 41   |
| 66   | System of Linear  Equations                         | 40   |
| 67   | Stirling Number of  the Second Kind                 | 40   |
| 68   | Polynomial Taylor  Shift                            | 39   |
| 69   | Sum of Totient  Function                            | 38   |
| 70   | Bernoulli Number                                    | 38   |
| 71   | Dynamic Tree Vertex  Add Subtree Sum                | 37   |
| 72   | Dynamic Tree Vertex  Set Path Composite             | 36   |
| 73   | Matrix Product                                      | 35   |
| 74   | Enumerate Palindromes                               | 34   |
| 75   | Enumerate Triangles                                 | 34   |
| 76   | Tetration Mod                                       | 34   |
| 77   | Dominator Tree                                      | 30   |
| 78   | Directed MST                                        | 30   |
| 79   | Determinant of Sparse  Matrix                       | 28   |
| 80   | Dynamic Sequence  Range Affine Range Sum            | 27   |
| 81   | Frequency Table of  Tree Distance                   | 27   |
| 82   | Manhattan MST                                       | 26   |
| 83   | Dynamic Graph Vertex  Add Component Sum             | 26   |
| 84   | Run Enumerate                                       | 25   |
| 85   | Nim Product  ($\mathbb{F}_{2^{64}}$)                | 24   |
| 86   | Predecessor Problem                                 | 22   |
| 87   | Dynamic Tree Subtree  Add Subtree Sum               | 20   |
| 88   | K-Shortest Walk                                     | 20   |
| 89   | Kth term of Linearly  Recurrent Sequence            | 20   |
| 90   | $\sum_{i=0}^{\infty}  r^i i^d$                      | 20   |
| 91   | Minimum cost b-flow                                 | 19   |
| 92   | $\sum_{i=0}^{n-1} r^i  i^d$                         | 18   |
| 93   | Chromatic Number                                    | 18   |
| 94   | Composition of Formal  Power Series                 | 14   |
| 95   | Division of  Polynomials                            | 12   |
| 96   | Three-Edge-Connected  Components                    | 12   |
| 97   | Edge Coloring of  Bipartite Graph                   | 11   |
| 98   | Kth Root(Mod)                                       | 11   |
| 99   | Hafnian of Matrix                                   | 10   |
| 100  | Inv of Polynomials                                  | 9    |
| 101  | Convex Layers                                       | 8    |
| 102  | Binomial Coefficient                                | 8    |
| 103  | Chordal Graph  Recognition                          | 7    |
| 104  | Tree Decomposition  (width 2)                       | 7    |
| 105  | Multivariate  Convolution                           | 6    |
| 106  | Convolution (mod  2^64)                             | 5    |
| 107  | Global Minimum Cut of  Dynamic Star Augmented Graph | 1    |
| 108  | Characteristic  Polynomial                          | 1    |