1059. Prime Factors

1059. Prime Factors (25)

时间限制

100 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

HE, Qinming

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 *…*p_m^k_m.

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 *…*p_m^k_m, where p_i's are prime factors of N in increasing order, and the exponent k_i is the number of p_i -- hence when there is only one p_i, k_i is 1 and must NOT be printed out.

Sample Input:

97532468

Sample Output:

97532468=2^2*11*17*101*1291

从最小的素数2开始往上找即可，注意输入为1时输出1=1。

#include <iostream>#include <algorithm>using namespace std;long long prime(long long s, long long n){long long r=n;for(int i=s;i<=sqrt(double(n));++i)if(n%i==0)return i;return r;}int main(){long long n;cin>>n;long long tmp=2,cnt;bool f=false;cout<<n<<"=";if(n==1)cout<<n<<endl;while(tmp<=n){cnt=0;tmp=prime(tmp,n);while(n%tmp==0){cnt++;n/=tmp;}if(f)cout<<"*";elsef=true;cout<<tmp;if(cnt>1)cout<<"^"<<cnt;}return 0;}