To find all the factors of a number and to use the basic theorem of arithmetic, here are two important applications:(1) A positive integer greater than 1 N, if its standard decomposition is: n= (P1^A1) * (P2^A2) ... (Pn^an)Then it's a number of numbers (1+A1) (1+A2) ..... (1+an).(2) The sum of its all positive factors is d (N) = (1+p1+...p1^an) (1+P2+...P2^A2) ..
This problem is also a more famous face test. Of course there are many variants.The main meaning of the topic is: to find the top n elements from a large array of data. Sorting is not allowed.There are two better ideas for this problem:Idea one: With a quick sort of thought, is thought, not to sort;Idea two: Use the maximum heap of thought. I temporarily only realized the idea of one, thinking two I realized after the will fill up. The idea is relat
Description:Count the number of prime numbers less than a non-negative number, n.Find the number of characters less than N.1, with the most simple algorithm is timed out. Public classSolution { Public intCountPrimes (intN) {if(N ){ return0; } intresult = 0; for(inti = 2; I ){ if(Isprimes (
Title Description:
The numbers that contain only the factors 2, 3, and 5 are called ugly Numbers (Ugly number). For example, 6, 8 are ugly numbers, but 14 is not, because it contains factor 7.We used to think of 1 as the first ugly number. Find the nth ugly number
Nine Chapters count judges Net-original websitehttp://www.jiuzhang.com/problem/65/TopicsThere is a special number, its prime factor is only possible 3,5,7, it can not be the other prime, we put this number from small to large sort, get 3, 5, 7, 9, 15 ... Now we are asking for the n
[j]*t); }}} sort (K.begin (), K.end ()); S.push_back (k[0]); mp[k[0]]++; } sort (S.begin (), S.end ()); printf ("The "th ugly number is 859963392."); return 0;}The final output is a well-calculated 1500th result. The input is the size of the ugly number.There is a wrong idea at first to do this question.My answer is to use 2,3,5,6,20,15,30 as the base to multiply the number of not
factorization: at for(intI=2; i*i) -{if(temp%i==0) {s.push_back (i); while(temp%i==0) temp/=i;} } -S.push_back (b);//because B itself may be a prime number, adding B to the vector, even if it is not a prime number, has no effect on the result. - for(intI=0; I//generates an approximate s.size (). -{Su=s[i];
Output768016016
AuthorSmallBeer (CRF)
Source hangdian ACM training team training competition (VII)
Recommendlcy
Question Analysis:
If this question is purely violent (it is to use two for loops to find the data scale from 1 ~ The number of elements in I that interact with I), the timeout is very high (n itself is large, and the brute force algorithm> O (n ^ 2) is also u
Title Source: POJ 2992 divisors
Test instructions: ...
Idea: The uniqueness of prime decomposition a number can be decomposed into several prime numbers multiplied P1^X1*P2^X2*...*PN^XN
Number of factors according to multiplication principle (x1+1) * (x2+1) *...* (xn+1)
Can not directly
Find the maximum
Problem descriptioneuler's totient function, Phi (n) [sometimes called the Phi function], is used to determine the number of numbers less than n which are relatively prime to n. for example, as 1, 2, 4, 5, 7, and 8, are all less than nine and relatively prime to nine, Phi (9) = 6.
Hg is the master of x
Tags: refresh Principle Ultraviolet A 4683 This question refers to a set with a maximum of 12 elements. Find the nth number that can only be divided by one of the sets and only one number. (N I did this by using the refresh principle. First, we will accumulate the number
Find the maximumTime limit:2000/1000 MS (java/others) Memory limit:65768/65768 K (java/others)Total submission (s): 1990 Accepted Submission (s): 837Problem Descriptioneuler ' s totient function,φ (n) [sometimes called the Phi function], is used to determine the number of Numbers less than n which is relatively prime to N. For example, as 1, 2, 4, 5, 7, and 8, is
factorization (prime factor or mass factor): that is, in addition to 1 can be divisible by a given positive integer number.prime numbers : The natural number in addition to 1 and it itself is no longer divisible by any other divisor.Composite : The number of natural numbers can be divisible (excluding 0) by other numbers except by 1 and by itself.Cases:6 of the q
Test instructions: Give N,m,p, C (n+m,n)%pBy using the integer decomposition of factorial, the form of C as factorial is decomposed into a prime-value expression.Code:#include Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced. To find the large number of combined HIT2813
1: Find the largest maximumSelect Max (Salary) from the employee where salary2. SortingSelect Salary from employee where Salary not in (select MAX (Salary) from employee) Order BY Salary desc LIMIT 1; Select (select DISTINCT Salary from Employee order by Salary Desc limit 1 offset 1) as secondheighestsalary; Find Nth Number:CREATE FUNCTION getnthhighestsalary
The following:
Define a Niconico-number, if X is Niconico-number, then all integers less than x and x coprime are a arithmetic progression, initially giving an array of n numbers, three operations:
1 L r Q How many niconico-number numbers are there in [L,r]
2 L R v for all numbers in [l,r] to V
3 k x Changes the number
Topic: The Fibonacci number is defined as: F (0) =0,f (1) =1,f (n) =f (n-1) +f (n-2) (N>1 and N is an integer)
If you write the Phillips series, it should be:
0 1 1 2 3 5 8 13 21 34 ...
If the 6th item is to be asked, it shall be 8.
Find the nth Xiangfi number.
Input Description: The input data contains no more th
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