## poj3090

maksyuki 发表于 oj 分类，标签:

Visible Lattice Points

A lattice point (xy) in the first quadrant (x and y are integers greater than or equal to 0), other than the origin, is visible from the origin if the line from (0, 0) to (xy) does not pass through any other lattice point >>继续阅读

## poj2478

maksyuki 发表于 oj 分类，标签:

Farey Sequence

The Farey Sequence Fn for any integer n with n >= 2 is the set of irreducible rational numbers a/b with 0 < a < b <= n and gcd(a,b) = 1 arranged in increasing order. The first few are

F2 = {1/2}

F3 = {1/3, 1/2, 2/3} >>继续阅读

## poj1284

maksyuki 发表于 oj 分类，标签:

Primitive Roots

We say that integer x, 0 < x < p, is a primitive root modulo odd prime p if and only if the set { (xi mod p) | 1 <= i <= p-1 } is equal to { 1, ..., p-1 }. For example, the consecutive powers of 3 modulo 7 are 3, 2, 6, 4 >>继续阅读

## hdu3501

maksyuki 发表于 oj 分类，标签:

Calculation 2

Problem Description

Given a positive integer N, your task is to calculate the sum >>继续阅读

## uva11424

maksyuki 发表于 oj 分类，标签:

Given the value of N, you will have to find the value of G. The definition of G is given below:G =i<N∑i=1j∑≤Nj=i+1GCD(i, j) Here GCD(i, j) means the greatest common divisor of integer i and integer j.

For those who have trouble understanding sum >>继续阅读

## lightoj1007

maksyuki 发表于 oj 分类，标签:

1007 - Mathematically Hard

In this problem, you will be given two integers a and b. You have to find the summation of the scores of the numbers from a to b (inclusive). The score of a number is defined as the following function.Mathematically some >>继续阅读

## bzoj2818

maksyuki 发表于 oj 分类，标签:

## bzoj2705

maksyuki 发表于 oj 分类，标签:

## Description

Longge的数学成绩非常好，并且他非常乐于挑战高难度的数学问题。现在问题来了：给定一个整数N，你需要求出∑gcd(i, N)(1<=i <=N)。

## bzoj2190

maksyuki 发表于 oj 分类，标签:

## sgu102

maksyuki 发表于 oj 分类，标签:

Coprimes

For given integer N (1<=N<=104) find amount of positive numbers not greater than N that coprime with N. Let us call two positive integers (say, A and B, for example) coprime if (and only if) their greatest common divisor is 1. >>继续阅读