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.
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
90 1234567891 18991325453139 12745267386521023 -1
Sample Output
2
3
3
5
1234567891
3
3
13
179
271
1381
2423
30971
411522630413
Source: Waterloo
Local Contest Sep. 28, 1996
分解因式。
#include <stdio.h> int main(){ long long i,n; while(~scanf("%lld",&n) && n>=0){ for(i=2 ; n>1 ;){ if(n%i == 0){ printf(" %lld\n",i); n/=i; } else{ i++; if(i*i>n){ printf(" %lld\n",n); break; } } } printf("\n"); } return 0; }
TOJ-1203 Factoring Large Numbers
原文：http://www.cnblogs.com/shenchuguimo/p/6306128.html