User contributions for Gispzjz
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14 May 2024
- 15:5515:55, 14 May 2024 diff hist +1 组合数学 (Spring 2024)/Problem Set 3 →Problem 5
- 15:5515:55, 14 May 2024 diff hist +2,925 N 组合数学 (Spring 2024)/Problem Set 3 Created page with "== Problem 1 == Solve the following two existence problems: * You are given <math>n</math> integers <math>a_1,a_2,\dots,a_n</math>, such that for each <math> 1\leq i\leq n</math> it holds that <math>i-n\leq a_i\leq i-1</math>. Show that there exists a '''nonempty''' subsequence (not necessarily consecutive) of these integers, whose sum is equal to <math> 0 </math>. (Hint: Consider <math> b_i=a_i-i </math>) * You are given two '''multisets''' <math> A </math> and <ma..."
- 15:2415:24, 14 May 2024 diff hist +61 组合数学 (Spring 2024) →Assignments
20 March 2024
- 12:1412:14, 20 March 2024 diff hist +11 组合数学 (Fall 2024)/Problem Set 1 →Problem 4 current
- 12:1412:14, 20 March 2024 diff hist +21 组合数学 (Fall 2024)/Problem Set 1 →Problem 4
- 12:1012:10, 20 March 2024 diff hist +38 组合数学 (Fall 2024)/Problem Set 1 →Problem 4
19 March 2024
- 14:5914:59, 19 March 2024 diff hist +8 组合数学 (Fall 2024)/Problem Set 1 →Problem 5
- 12:4412:44, 19 March 2024 diff hist +28 组合数学 (Fall 2024)/Problem Set 1 →Problem 5
- 12:4312:43, 19 March 2024 diff hist +17 组合数学 (Fall 2024)/Problem Set 1 →Problem 4
- 12:4312:43, 19 March 2024 diff hist +17 组合数学 (Fall 2024)/Problem Set 1 →Problem 3
- 12:4212:42, 19 March 2024 diff hist +6 组合数学 (Fall 2024)/Problem Set 1 →Problem 5
- 12:4212:42, 19 March 2024 diff hist +1,642 N 组合数学 (Fall 2024)/Problem Set 1 Created page with "== Problem 1 == How many <math>n\times m</math> matrices of <math>0</math>'s and <math>1</math>'s are there, such that every row and column contains an even number of <math>1</math>'s? An odd number of <math>1</math>'s? == Problem 2 == * There is a set of <math>2n</math> people: <math>n</math> male and <math>n</math> female. A good party is a set with the same number of male and female. How many possibilities are there to build such a good party? * Try to express the a..."
- 12:4212:42, 19 March 2024 diff hist +53 组合数学 (Spring 2024) →Assignments
8 June 2023
- 14:2614:26, 8 June 2023 diff hist −30 组合数学 (Fall 2023)/Problem Set 4 →Problem 1
- 14:2614:26, 8 June 2023 diff hist +31 组合数学 (Fall 2023)/Problem Set 4 →Problem 1
- 14:2214:22, 8 June 2023 diff hist +136 组合数学 (Fall 2023)/Problem Set 4 →Problem 1
- 14:2114:21, 8 June 2023 diff hist +1 组合数学 (Fall 2023)/Problem Set 4 →Problem 1
- 14:2114:21, 8 June 2023 diff hist +1 组合数学 (Fall 2023)/Problem Set 4 →Problem 5
- 14:2014:20, 8 June 2023 diff hist +4 组合数学 (Fall 2023)/Problem Set 4 →Problem 5
- 14:2014:20, 8 June 2023 diff hist +517 组合数学 (Fall 2023)/Problem Set 4 →Problem 5
- 14:1714:17, 8 June 2023 diff hist +102 组合数学 (Fall 2023)/Problem Set 4 →Problem 5
- 14:1514:15, 8 June 2023 diff hist +1,759 N 组合数学 (Fall 2023)/Problem Set 4 Created page with "== Problem 1 == Prove that * <math>R(4,3)\leq 9</math>. (Hint: Proof by contradiction. Color the edges of <math>K_9</math> in red and blue, and assume that there are no red triangles and no blue <math>4</math>-cliques. Try to determine the number of red and blue edges adjacent to each vertex) * <math>R(4,4)\leq 18</math>. ==Problem 2== We color each non-empty subset of <math>[n]=\{1,2,\ldots,n\}</math> with one of the <math>r</math> colors in <math>[r]</math>. Show tha..."
- 13:2813:28, 8 June 2023 diff hist 0 组合数学 (Spring 2023) →Assignments
- 13:2713:27, 8 June 2023 diff hist +59 组合数学 (Spring 2023) →Assignments
13 April 2023
- 13:2313:23, 13 April 2023 diff hist −2 组合数学 (Fall 2023)/Problem Set 2 →Problem 5
- 13:2213:22, 13 April 2023 diff hist +1 组合数学 (Fall 2023)/Problem Set 2 →Problem 5
- 13:2113:21, 13 April 2023 diff hist +495 组合数学 (Fall 2023)/Problem Set 2 →Problem 4
- 13:0813:08, 13 April 2023 diff hist +216 组合数学 (Fall 2023)/Problem Set 2 →Problem 1
- 13:0813:08, 13 April 2023 diff hist +889 组合数学 (Fall 2023)/Problem Set 2 →Problem 2
- 13:0813:08, 13 April 2023 diff hist −888 组合数学 (Fall 2023)/Problem Set 2 →Problem 1
- 13:0813:08, 13 April 2023 diff hist −216 组合数学 (Fall 2023)/Problem Set 2 →Problem 2
- 13:0813:08, 13 April 2023 diff hist +276 组合数学 (Fall 2023)/Problem Set 2 →Problem 1
- 13:0513:05, 13 April 2023 diff hist +611 组合数学 (Fall 2023)/Problem Set 2 →Problem 1
- 12:5412:54, 13 April 2023 diff hist +1 组合数学 (Fall 2023)/Problem Set 2 →Problem 3
- 12:5312:53, 13 April 2023 diff hist −11 组合数学 (Fall 2023)/Problem Set 2 →Problem 4
- 12:5312:53, 13 April 2023 diff hist +430 组合数学 (Fall 2023)/Problem Set 2 →Problem 3
- 12:5212:52, 13 April 2023 diff hist +2 组合数学 (Fall 2023)/Problem Set 2 →Problem 3
- 12:5212:52, 13 April 2023 diff hist +51 组合数学 (Fall 2023)/Problem Set 2 →Problem 2
- 12:5012:50, 13 April 2023 diff hist +165 组合数学 (Fall 2023)/Problem Set 2 →Problem 2
- 12:4712:47, 13 April 2023 diff hist +35 组合数学 (Fall 2023)/Problem Set 2 →Problem 1
- 12:4712:47, 13 April 2023 diff hist +17 组合数学 (Fall 2023)/Problem Set 2 No edit summary
- 12:4612:46, 13 April 2023 diff hist +728 N 组合数学 (Fall 2023)/Problem Set 2 Created page with "Let <math>S=\{P_1,...,P_n\}</math> be a set of properties, and let <math>f_k</math> (respectively, <math>f_{\geq k}</math>) denote the number of objects in a finite set <math>U</math> that have '''exactly''' <math>k</math> (respectively, '''at least''' <math>k</math>) of the properties. Let <math>A_i</math> denote the set of objects satisfies <math>P_i</math> in <math>U</math>, for any <math>I\subseteq\{1,...,n\}</math>, we denote <math>A_I=\bigcap_{i\in I}A_i</math> wi..."
- 12:1412:14, 13 April 2023 diff hist +157 组合数学 (Spring 2023) →Assignments
13 February 2023
12 December 2022
- 07:5107:51, 12 December 2022 diff hist −1 高级算法 (Fall 2022)/Problem Set 4 →Problem 7
- 07:5107:51, 12 December 2022 diff hist +7 高级算法 (Fall 2022)/Problem Set 4 →Problem 7
- 07:5007:50, 12 December 2022 diff hist −1 高级算法 (Fall 2022)/Problem Set 4 →Problem 7
- 07:5007:50, 12 December 2022 diff hist +692 高级算法 (Fall 2022)/Problem Set 4 →Problem 7
- 07:4607:46, 12 December 2022 diff hist −1 高级算法 (Fall 2022)/Problem Set 4 →Problem 7
- 07:4507:45, 12 December 2022 diff hist +585 高级算法 (Fall 2022)/Problem Set 4 →Problem 6