Time Limit: 5000MS Memory Limit: 131072K Case Time Limit: 2000MS Description N children are sitting in a circle to play a game. The children are numbered from 1 to N in clockwise order. Each of them has a card with a non-zero integer on it in his/her
Goldbach's Conjecture Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 35214 Accepted: 13493 Description In 1742, Christian Goldbach, a German amateur mathematician, sent a letter to Leonhard Euler in which he made the following conject
题目是求fun(n)的值 fun(n)= Gcd(3)+Gcd(4)+…+Gcd(i)+…+Gcd(n).Gcd(n)=gcd(C[n][1],C[n][2],……,C[n][n-1])C[n][k] means the number of way to choose k things from n things. n最大一百万,马上反映到可能是递推打表. 首先肯定是推公式了,fun(n)其实就是Gcd(n)的一个前n项和,没意义,直接看Gcd(n),把前几项列出来,发现公式是Gcd(n) =
Double Happiness On the math lesson a teacher asked each pupil to come up with his own lucky numbers. As a fan of number theory Peter chose prime numbers. Bob was more original. He said that number t is his lucky number, if it can be represented as:t
描述 http://poj.org/problem?id=2739 多次询问,对于一个给定的n,求有多少组连续的素数,满足连续素数之和为n. Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 22737 Accepted: 12432 Description Some positive integers can be represented by a su
Problem Description Everybody knows any number can be combined by the prime number. Now, your task is telling me what position of the largest prime factor. The position of prime 2 is 1, prime 3 is 2, and prime 5 is 3, etc. Specially, LPF(1) = 0. In