#include<iostream>

using namespace std;

#define MAX_LEN 256
//a:乘数1	0位保存整数位数
//c:保存积
inline void mul( int c[],int a[], int b[])
{
	int i,j,k,l;
	int lena,lenb;

	lena = a[0] + 1;
	lenb = b[0] + 1;

	for(i=1;i <= lenb;i++)
	{
		k=i;
		for(j=1;j <= lena;j++)
		{
			c[k] = c[k]+a[j]*b[i];
			l = k;
			while(c[l]>=10)
			{
				c[l+1] += (c[l]/10);
				c[l] %= 10;
				l++;
			}		
			k++;
		}


	}
	
	c[0] = l - 1; // len

}



int main()
{

	int n; 
	int i,j,k;

	int ppos; //point's position
	int len; //float len

	char s[64];

	int strNum[ MAX_LEN ]; // work array
	int strInt[MAX_LEN];
	int Tmp[MAX_LEN];

	while(cin>>s>>n)
	{
		
		ppos = 0;
		memset(strNum,0,MAX_LEN*sizeof(int));
		memset(strInt,0,MAX_LEN*sizeof(int));

		strNum[0] = len = strlen( s ) - 1; // charaters and .', so minus 2

		//find point
		for( i = 0; i< len; i++)
		{
			if( s[i] != '.' )
			{
				ppos++;
			}
			else
				break;
		}

		//input range check
		if( n > 25 || n < 0 )
			continue;

		if( n == 0 )
		{
			cout<<1<<endl;
			continue;
		}


		//change to array
		j=1;
		for( i=len; i >= 0; i-- )
		{
			if( s[i] != '.' )
				strInt[j++] = s[i]  - '0' ;
		}
		j--;
		strInt[0] = j;

		i = 1;
		for( ;i < j && strInt[i]==0 ;i++ );
		if( i != 1 )
		{
			for( k = 1 ; i <= j ; k++,i++)
			{
				strInt[ k ] = strInt[ i];
				strInt[ i] = 0;
			}
			
			len = strInt[0] = k - 1;
		}

		//0.0
		if( len == 1 && strInt[1] == 0 )
		{
			cout<<0<<endl;
			continue;
		}
		
		
		
		//calc
		mul( strNum, strInt, strInt);
		for( i = 1; i < n - 1; i++ )
		{
			//copy strInt to strIntTmp
			memset(Tmp,0,MAX_LEN*sizeof(int));
			for(j=0;j <= (strNum[0]+1) ;j++)
				Tmp[j] = strNum[j];

			memset(strNum,0,MAX_LEN*sizeof(int));
			mul( strNum,Tmp, strInt);

		}

		//insert point
		j = (len - ppos)*n; 
		for( i = strNum[0]; strNum[i]==0 && i>j; i--);
		for( ; i>j; i--)
			cout<<(char)(strNum[i] + '0');

		if( i != 0 )
			cout<<'.';


		for( j=1; strNum[j]==0 && j < i; j++);
		for(;i>j-1;i--)
			cout<<(char)(strNum[i] + '0');
		cout<<endl;


		//initilize
		memset(s,0,8);


	}

	return 0;
}
-----------
测试页上数据都OK
连论坛上看到的 
0.0 3 
1.000 3 
12 0
...
等都通过了,但是就是WA~~~~究竟还要什么测试数据呢?
(我看了其他代码AC的但是有数据也通不过呀~~~为什么~~~~~:(