这题主要是推公式…… ;}…

思路:五边形数定理!!! 五边形数定理是一个由欧拉发现的数学定理,描述欧拉函数展开式的特性.欧拉函数的展开式如下: 亦即 欧拉函数展开后,有些次方项被消去,只留下次方项为1, 2, 5, 7, 12, ...的项次,留下来的次方恰为广义五边形数. 若将上式视为幂级数,其收敛半径为1,不过若只是当作形式幂级数(formal power series)来考虑,就不会考虑其收敛半径. 欧拉函数的倒数是分割函数的母函数,亦即: 其中为k的分割函数. 上式配合五边形数定理,可以得到 考虑项的系数,在 n>…

Integer Partition Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 524 Accepted Submission(s): 238 Problem Description Given n, k, calculate the number of different (unordered) partitions of n such…

Partition Time Limit: 6000/3000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 954 Accepted Submission(s): 545 Problem Description How many ways can the numbers 1 to 15 be added together to make 15? The technical term…

Partition Time Limit: 6000/3000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 954 Accepted Submission(s): 545 Problem Description How many ways can the numbers 1 to 15 be added together to make 15? The technical term…

ACM ICPC Central Europe Regional Contest 2013 Jagiellonian University Kraków Problem A: Rubik’s RectangleProblem B: What does the fox say?Problem C: Magical GCDProblem D: SubwayProblem E: EscapeProblem F: DraughtsProblem G: History courseProblem H: C…

传送门:http://acm.hdu.edu.cn/showproblem.php?pid=6300 Triangle Partition Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 132768/132768 K (Java/Others)Total Submission(s): 2964    Accepted Submission(s): 1474Special Judge Problem Description Chia…

JSU 2013 Summer Individual Ranking Contest - 5 密码:本套题选题权归JSU所有,需要密码请联系(http://blog.csdn.net/yew1eb). 一.套题分析:该套题难度不大,适合入门有一定基础的ACMer用于练习. 二.考点:逻辑思维.基础数论.数位运算基础.深度优先搜索.动态规划. 三.竞赛形式:个人赛 四.解题时间:3小时 五.题目情况: A. BNU ACM校队时间安排表        B. 硬币水题II        C. 沙漠之…

Redraw Beautiful Drawings Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description Alice and Bob are playing together. Alice is crazy about art and she has visited many museums around the world. She has…

任意门:http://acm.hdu.edu.cn/showproblem.php?pid=6319 Problem A. Ascending Rating Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 5943    Accepted Submission(s): 2004 Problem Description Before…