zoukankan      html  css  js  c++  java
  • Kattis之旅——Prime Reduction

    A prime number p≥2 is an integer which is evenly divisible by only two integers: 1 and p. A composite integer is one which is not prime. The fundamental theorem of arithmetic says that any integer x can be expressed uniquely as a set of prime factors – those prime numbers which, when multiplied together, give x. Consider the prime factorization of the following numbers:
    10=2×5 16=2×2×2×2 231=3×7×11
    Consider the following process, which we’ll call prime reduction. Given an input x:

    if xx is prime, print xx and stop
    factor xx into its prime factors p1,p2,…,pk
    let x=p1+p2+⋯+pk
    go back to step 1
    Write a program that implements prime reduction.

    Input
    Input consists of a sequence of up to 2000020000 integers, one per line, in the range 22 to 109109. The number 44 will not be included in the sequence (try it to see why it’s excluded). Input ends with a line containing only the number 4.

    Output
    For each integer, print the value produced by prime reduction executed on that input, followed by the number of times the first line of the process executed.

    Sample Input 1Sample Output 1
    2
    3
    5
    76
    100
    2001
    4
    
    2 1
    3 1
    5 1
    23 2
    5 5
    5 6

    大意就是:给你一个数x——1、如果x是素数,直接输出x以及循环的步数。2、如果不是,那就x分解质因数,把所有质因数之和给x,步数+1,执行第一步。

     //Asimple
    #include <bits/stdc++.h>
    using namespace std;
    typedef long long ll;
    ll n, m, s, res, ans, len, T, k, num;

    bool
    is_pr(ll n) { for(int i=2; i*i<=n; i++) { if( n%i==0 ) return false; } return true; } ll solve(ll n){ ll ans = 0; int i = 2; while( n>1 ) { if( n%i==0 ) { ans += i; n /= i; if( is_pr(n) ) {//这步是关键,不写超时 ans += n; break; } } else ++i; } return ans; } void input() { while( cin >> n) { res = 1; if( n == 4 ) break; while( !is_pr(n) ) { n = solve(n); res ++; } cout << n << " " << res << endl; } } int main(){ input(); return 0; }
  • 相关阅读:
    获取Enum枚举值描述的几法方法
    Android开发入门 Button事件实现的方法(原创)
    最有价值的.Net第三方控件
    Eclipse快捷键大全(转载)
    recovery教程
    XP系统通过无线网卡共享宽带给其他设备,正确的共享设置(修正版,绝对可行)
    使用Eclipse写QT
    Android 4.0模拟器弹出“谷歌拼音输入法”已停止运行的解决方法
    C# 枚举用法总结
    谷歌安卓系统使用必读,什么是root, Recovery, Radio, APP TO SD, Rom
  • 原文地址:https://www.cnblogs.com/Asimple/p/6785476.html
Copyright © 2011-2022 走看看