10392 - Factoring Large Numbers
来源:互联网 发布:淘宝可以删差评吗 编辑:程序博客网 时间:2024/05/19 12:16
Problem F: Factoring Large Numbers
One of the central ideas behind much cryptography is that factoring large numbers is computationally intensive. In this context one might use a 100 digit number that was a product of two 50 digit prime numbers. Even with the fastest projected computers this factorization will take hundreds of years.
You don't have those computers available, but if you are clever you can still factor fairly large numbers.
Input
The input will be a sequence of integer values, one per line, terminated by a negative number. The numbers will fit in gcc's long long int
datatype. You may assume that there will be at most one factor more than 1000000.
Output
Each positive number from the input must be factored and all factors (other than 1) printed out. The factors must be printed in ascending order with 4 leading spaces preceding a left justified number, and followed by a single blank line.
Sample Input
9012345678911899132545313912745267386521023-1
Sample Output
2 3 3 5 1234567891 3 3 13 179 271 1381 2423 30971 411522630413
把一个long long类型的大数分解质因数,保证最多只有一个大于1000000的质因数。那就直接用素数筛选法把1000000以内的素数找出来。水题
#include<iostream>#include<cstdio>#include<cmath>#include<cstring>#define maxn 1000010using namespace std;int a[maxn]= {0};int main (){ long long n; int i,j; for (i=2; i<1000000; i++) if (!a[i]) for (j=2*i; j<1000000; j+=i) a[j]=1; while(cin>>n) { if (n<0) break; for (i=2; i<1000000; i++) if (!a[i]) { while(n%i==0) { printf(" %d\n",i); n/=i; } } if (n>1) printf(" %lld\n",n); cout<<endl; } return 0;}
- 10392 - Factoring Large Numbers
- 10392 - Factoring Large Numbers
- 10392 - Factoring Large Numbers
- 10392 - Factoring Large Numbers
- UVa 10392 Factoring Large Numbers
- uva 10392 Factoring Large Numbers
- uva 10392 - Factoring Large Numbers
- UVa 10392 - Factoring Large Numbers
- uva 10392 - Factoring Large Numbers
- uva-10392 - Factoring Large Numbers
- UVa 10392 - Factoring Large Numbers
- Uva 10392 - Factoring Large Numbers
- UVa 10392 - Factoring Large Numbers
- UVa 10392 - Factoring Large Numbers
- UVA 10392 Factoring Large Numbers
- UVa 10392: Factoring Large Numbers
- uva 10392 - Factoring Large Numbers
- uva 10392 Factoring Large Numbers
- (spring+hibernate)java.lang.NoSuchMethodError: org.objectweb.asm.ClassVisitor.visit(IILjava/lang/Str
- 个人重构机房收费系统DataGridView显示用户信息
- Oracle Database 12c创建Pluggable Database的两种方式及拔出、插入、删除Pluggable Database
- 大数的四则运算
- Knockout.js随手记(7)
- 10392 - Factoring Large Numbers
- debugfs, tmpfs, proc, sysfs 介绍
- android 中 系统日期时间的获取
- 学生信息管理系统问题(一)
- http://acm.hdu.edu.cn/showproblem.php?pid=1789
- Linux┊理解devfs、sysfs、udev
- Windows服务安装后设置自动启动与允许服务与桌面交互的方法
- Android 的系统属性(SystemProperties)设置分析
- @Scope("prototype")其实很重要