By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the 10 001st prime number? max1 = 10001 a = [2] i = 3 while len(a) < max1: flag = 0 for j in a: if j > i**0.5: break if i%j == 0: flag = 1 b…

The arithmetic sequence, 1487, 4817, 8147, in which each of the terms increases by 3330, is unusual in two ways: (i) each of the three terms are prime, and, (ii) each of the 4-digit numbers are permutations of one another. There are no arithmetic seq…

By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the 10 001st prime number? #include <stdio.h> #include <string.h> #include <ctype.h> #include <math.h> int prim(int n) { i…

Sieve of Eratosthenes (素数筛选算法) Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number. For example, if n is 10, the output should be “2, 3, 5, 7″. If n is 20, the output should be “2, 3, 5, 7, 11, 13,…

By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the 10 001st prime number? 译文: 观察第一组质数可知,第6位质数为13,那么第10001位质数是多少呢? ============================ 第一次code: import java.util.ArrayList; import j…

The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143 ? 欧拉题里很多是关于求质数,求质数的方法很多,我推荐的是筛选法,效率高,也很好理解.百度一下就有详细说明. def primeslist(max): a = [True]*(max+1) # 创建一个list,下标的位置就代表数字 a[0],a[1]=False,False # 0…

We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once. For example, 2143 is a 4-digit pandigital and is also prime. What is the largest n-digit pandigital prime that exists? #include <iostream> #incl…

本题来自 Project Euler 第7题:https://projecteuler.net/problem=7 # Project Euler: Problem 7: 10001st prime # By listing the first six prime numbers: # 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. # What is the 10 001st prime number? # Answer…

题目链接:http://poj.org/problem?id=3126 Prime Path Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 32036   Accepted: 17373 Description The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they…

题目链接:http://poj.org/problem?id=3126 Prime Path Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 22936   Accepted: 12706 Description The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they…