[UVa]160:Factors and Factorials

這題不用先乘出答案，把階乘的每一項一個一個因式分解再加起來即可得解。

P.S. 我沒用到質數XD"" 我直接除到根號這樣XDDDDDDD

[C](0.012)

	#include<stdio.h>
	#include<math.h>
	#define ERROR 0.000000001
	int main()
	{
	int N;
	while( scanf( "%d", &N ) != EOF && N != 0 )
	{
	int i;
	int prime_count[105] = {0};
	for( i = N ; i >= 2 ; i-- )
	{
	int temp = i;
	int j;
	int sqrt_i = (int)( sqrt( (double)temp ) + ERROR );
	for( j = 2 ; j <= sqrt_i ; j++ )
	while( !(temp % j) )
	{
	prime_count[j]++;
	temp /= j;
	}
	if( temp > 1 )
	prime_count[temp]++;
	}
	printf( "%3d! =", N );
	int count = 0;
	for( i = 2 ; i <= N ; i++ )
	{
	if( prime_count[i] )
	{
	if( !(count % 15) && count != 0 )
	printf( "\n " );
	count++;
	printf( "%3d", prime_count[i] );
	}
	}
	printf( "\n" );
	}
	return 0;
	}

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