sgzqc的专栏

【题目】Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...By consi

【题目】The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:1, 3, 6, 10, 1

【题目】The following iterative sequence is defined for the set of positive integers:n → n/2 (n is even)n → 3n + 1 (n is odd)Using the rule above and starting with 13, we generate the followin

【题目】在20X20的网格中同一直线上四个数的最大乘积是多少？In the 20×20 grid below, four numbers along a diagonal line have been marked in red.08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 0849 49 99 40 17 81

【题目】The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.Find the sum of all the primes below two million.【翻译】10以下的质数的和是2 + 3 + 5 + 7 = 17.找出两百万以下所有质数的和。【思路】依旧暴力法 【代码】bool isPr

【题目】The sum of the squares of the first ten natural numbers is,12 + 22 + ... + 102 = 385The square of the sum of the first ten natural numbers is,(1 + 2 + ... + 10)2 = 552 = 3025Hence th

【题目】A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.Find the largest palindrome made from the product of two

【题目一】If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.Find the sum of all the multiples of 3 or 5 below 1000.【翻译】10以

【题目】A Pythagorean triplet is a set of three natural numbers, a b c, for which,a2 + b2 = c2For example, 32 + 42 = 9 + 16 = 25 = 52.There exists exactly one Pythagorean triplet for which a +

【题目】The four adjacent digits in the 1000-digit number that have the greatest product are 9 × 9 × 8 × 9 = 5832.7316717653133062491922511967442657474235534919493496983520312774506326239578318016

【题目】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?【翻译】前六个质数是2,3,5,7,11和13，其中第6个是13.第10001个质数是多少？

【题目】The prime factors of 13195 are 5, 7, 13 and 29.What is the largest prime factor of the number 600851475143 ?【翻译】13195的质数因子有5,7,13和29.600851475143的最大质数因子是多少？【思路】求一个数分解质因数，要从最小

【题目】2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.What is the smallest positive number that is evenly divisible by all of the numbers

【题目】Work out the first ten digits of the sum of the following one-hundred 50-digit numbers.37107287533902102798797998220837590246510135740250463769376774900097126481248969700780504170182605387