People in Silverland use square coins. Not only they have square shapes but also their values are square numbers. Coins with values of all square numbers up to 289 (=17^2), i.e., 1-credit coins, 4-credit coins, 9-credit coins, ...,
and 289-credit coins, are available in Silverland.
There are four combinations of coins to pay ten credits:

ten 1-credit coins,
one 4-credit coin and six 1-credit coins,
two 4-credit coins and two 1-credit coins, and
one 9-credit coin and one 1-credit coin.

Your mission is to count the number of ways to pay a given amount using coins of Silverland.

The input consists of lines each containing an integer meaning an amount to be paid, followed by a line containing a zero. You may assume that all the amounts are positive and less than 300.

For each of the given amount, one line containing a single integer representing the number of combinations of coins should be output. No other characters should appear in the output.

2
10
30
0

1
4
27

做法：仍然是最基本的母函数，只需要把完全平方数事先预处理存起来即可

我的代码：

#include<stdio.h>
#include<string.h>

int squre[18];
int c1[305],c2[305];

void init()
{
	int i;
	for(i=1;i<=17;i++)
		squre[i]=i*i;
}

int main()
{
	int n,i,j,k;
	init();
	while(scanf("%d",&n)!=EOF)
	{
		if(n==0)
			break;
		for(i=0;i<=n;i++)
		{
			c1[i]=1;
			c2[i]=0;
		}
		for(i=2;i*i<=n;i++)
		{
			for(j=0;j<=n;j++)
				for(k=0;k+j<=n;k=k+squre[i])
					c2[k+j]=c2[k+j]+c1[j];
			for(j=0;j<=n;j++)
			{
				c1[j]=c2[j];
				c2[j]=0;
			}
		}
		printf("%d\n",c1[n]);
	}
	return 0;
}