Given any positive integer N, you are supposed to find all of its prime factors, and write them in the format N = p1^k1 * p2^k2 …pm^km.
Input Specification:
Each input file contains one test case which gives a positive integer N in the range of long int.
Output Specification:
Factor N in the format N = p1^k1 * p2^k2 …pm^km, where pi‘s are prime factors of N in increasing order, and the exponent ki is the number of pi -- hence when there is only one pi, ki is 1 and must NOT be printed out.
Sample Input:
97532468
Sample Output:
97532468=2^2*11*17*101*1291
分析
在输入的数据为1时输出1=1；#include<iostream>
#include<math.h>
#include<map>
using namespace std;
bool isprime(long int n){
for(int i=2;i<=sqrt(n);i++)
if(n%i==0) return false;
return true;
}
int main(){
long int p,t=1,q;
cin>>p;
q=p;
map<long int,int> mapp;
for(int i=2;i<=p;i++){
while(isprime(i)&&p%i==0){
p/=i;
t*=i;
mapp[i]++;
}
if(t==q) break;
}
printf("%d=",q);
if(q==1) printf("1");
for(auto it=mapp.begin();it!=mapp.end();it++){
if(it!=mapp.begin())
printf("*");
if(it->second==1)
printf("%d",it->first);
else
printf("%d^%d",it->first,it->second);
}
return 0;
}