n阶乘的素数分解

/****************************** 
作者：cncoderalex 
博客：http://blog.youkuaiyun.com/cncoderalex 
*******************************/

#include <iostream>
#include <memory>
#include <string>
#include <stack>
#include <algorithm>

using namespace std;

bool Mark[1000];
int Primes[1000];
int PrimeSize;

int PrimeFactorExp[1000];

void CalcPrimes()
{
	PrimeSize = 0;
	for (int i = 2; i < 1000; i++)
	{
		if (Mark[i])
			continue;

		Primes[PrimeSize++] = i;
		for (int j = i * i; j < 1000; j += i)
		{
			Mark[j] = true;
		}
	}
}

void DecompositePrimeFactor(int n)
{
	for (int i = 0; i < PrimeSize; i++)
	{
		int t = n;
		while (t)
		{
			t /= Primes[i];
			PrimeFactorExp[i] += t;
		}
	}
}

void PrintAns()
{
	bool bPrinted = false;
	for (int i = 0; i < PrimeSize; i++)
	{
		if (PrimeFactorExp[i] > 0)
		{
			if (bPrinted)
			{
				printf(" * %d^%d", Primes[i], PrimeFactorExp[i]);
			}
			else
			{
				printf("%d^%d", Primes[i], PrimeFactorExp[i]);

				bPrinted = true;
			}
		}
	}

	printf("\n");
}

void PrintPrimes()
{
	for (int i = 0; i < PrimeSize; i++)
	{
		if (i % 10 == 0)
			printf("\n");
		printf("%d ", Primes[i]);
	}

	printf("\n\n");

}

int main()
{
	printf("http://blog.youkuaiyun.com/cncoderalex");
	printf("\n");

	CalcPrimes();
	PrintPrimes();

	DecompositePrimeFactor(10);
	PrintAns();

	system("pause");

	return 0;
}