整数的因子分解

#include<stdio.h>
#include<math.h>
#include<string.h>
#include<map>
using namespace std;

int main()
{
    int n;
    map<int,int> factor;

    while(true)
    {
        scanf("%d",&n);    
        
        int i;
        for(i=2;i*i<=n;i++)
            while(n%i==0)
            {
                factor[i]++;n/=i;     //用map来记录因子以及因子的次幂

            }

        if(n!=1) factor[n]++;         //对于素数的考虑


        for(map<int,int>::iterator iter=factor.begin();iter!=factor.end();iter++)
        {
            if(iter!=factor.begin()) printf("×");
            printf("%d^%d",iter->first,iter->second);
        }
        printf("\n");

        factor.clear();
    }
    
    return 0;
}

 

因子分解结果:x=a1^p1*a2^p2*……*an^pn

例如：12=2^2*3^1