zoukankan      html  css  js  c++  java
  • Visible Lattice Points

    Visible Lattice Points
    Time Limit: 1000MS   Memory Limit: 65536K
    Total Submissions: 6379   Accepted: 3803

    Description

    A lattice point (x, y) 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 (x, y) does not pass through any other lattice point. For example, the point (4, 2) is not visible since the line from the origin passes through (2, 1). The figure below shows the points (x, y) with 0 ≤ x, y ≤ 5 with lines from the origin to the visible points.

    Write a program which, given a value for the size, N, computes the number of visible points (x, y) with 0 ≤ x, yN.

    Input

    The first line of input contains a single integer C (1 ≤ C ≤ 1000) which is the number of datasets that follow.

    Each dataset consists of a single line of input containing a single integer N (1 ≤ N ≤ 1000), which is the size.

    Output

    For each dataset, there is to be one line of output consisting of: the dataset number starting at 1, a single space, the size, a single space and the number of visible points for that size.

    Sample Input

    4
    2
    4
    5
    231

    Sample Output

    1 2 5
    2 4 13
    3 5 21
    4 231 32549

    思路:欧拉函数;有一个点的坐标为(x,y)那么可以写成gcd(x,y)(x/gcd,y/gcd)
    那么这个点必定和(x/gcd,y/gcd)在同一直线上,那么x/gcd,与y/gcd互素所以求欧拉函数就行。
     1 #include<stdio.h>
     2 #include<algorithm>
     3 #include<iostream>
     4 #include<stdlib.h>
     5 #include<string.h>
     6 #include<queue>
     7 #include<stack>
     8 #include<math.h>
     9 #include<vector>
    10 using namespace std;
    11 typedef long long LL;
    12 int gcd(int n,int m);
    13 int oula[2000];
    14 bool prime[2000];
    15 int ans[1000];
    16 int main(void)
    17 {
    18         int i,j,k;
    19         int n,m;
    20         scanf("%d",&k);
    21         int an=0;
    22         for(i=2; i<=100; i++)
    23         {
    24                 if(!prime[i])
    25                 {
    26                         for(j=i; (i*j)<=1000; j++)
    27                         {
    28                                 prime[i*j]=true;
    29                         }
    30                 }
    31         }
    32         int ak=0;
    33         for(i=2; i<=1000; i++)
    34         {
    35                 if(!prime[i])
    36                 {
    37                         ans[ak++]=i;
    38                 }
    39         }
    40         for(i=0; i<=1000; i++)
    41         {
    42                 oula[i]=i;
    43         }
    44         for(i=0; i<ak; i++)
    45         {
    46                 for(j=1; j*ans[i]<=1000; j++)
    47                 {
    48                         oula[ans[i]*j]/=ans[i];
    49                         oula[ans[i]*j]*=ans[i]-1;
    50                 }
    51         }
    52         while(k--)
    53         {
    54                 an++;
    55                 scanf("%d",&n);
    56                 int sum=0;
    57                 for(i=1; i<=n; i++)
    58                 {
    59                      sum+=oula[i];
    60                 }
    61                 sum*=2;printf("%d %d ",an,n);
    62                 printf("%d
    ",sum+1);
    63         }
    64 }
    65 int gcd(int n,int m)
    66 {
    67         if(m==0)
    68         {
    69                 return n;
    70 
    71         }
    72         else if(n%m==0)
    73         {
    74                 return m;
    75         }
    76         else return gcd(m,n%m);
    77 }
    
    
    油!油!you@
  • 相关阅读:
    IIS7 503错误 Service Unavailable
    android错误系列之导出数据库出错Failed to pull selection
    android学习笔记(入门篇)
    使用cmd命令删除文件夹下所有文件
    vue 动态插入组件
    js获取当前时间
    获取带参值
    以毫秒为单位的时间长度转化为时分秒时间格式的时间长度
    js如何复制一个对象?
    想在已创建的Vue工程里引入vux组件
  • 原文地址:https://www.cnblogs.com/zzuli2sjy/p/5534292.html
Copyright © 2011-2022 走看看