PAT_1059: Prime Factors

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

備註：簡單題

#include<stdio.h>
#include<math.h>

int IsPrime(long int n)
{
	for(long int i=2;i<=sqrt((double)n);i++)
	{
		if(n%i==0)
			return 0;
	}
	return 1;
}

int main()
{
	long int n;
	scanf("%ld",&n);

	if(IsPrime(n))
	{
		printf("%ld=%ld",n,n);
		return 0;
	}
	printf("%ld=",n);
	for(long int i=2;i<=n;i++)
	{
		if(IsPrime(i))
		{
			int exp = 0;
			while(n%i==0)
			{
				n=n/i;
				exp++;
			}
			if(exp==0)
				continue;
			else if(exp==1)
			{
				if(n==1)
				{
					printf("%ld",i);
					break;
				}
				else
					printf("%ld*",i);
			}
			else
			{
				if(n==1)
				{
					printf("%ld^%d",i,exp);
					break;
				}
				else
					printf("%ld^%d*",i,exp);
			}
		}
	}

	return 0;
}