[HDU-1398] 生成函数基础题

还是经典生成函数：

(1+x^i)

#include<iostream>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
typedef long long ll;
#define ls (o<<1)
#define rs (o<<1|1)
#define pb push_back

const int M = 300+7;
/*
int head[M],cnt=1;
void init(){cnt=1,memset(head,0,sizeof(head));}
struct EDGE{int to,nxt,w;}ee[M*2];
void add(int x,int y,int w){ee[++cnt].nxt=head[x],ee[cnt].w=w,ee[cnt].to=y,head[x]=cnt;}
*/
int f[2][M];
int w[21];
int main()
{
	ios::sync_with_stdio(false);
  	cin.tie(0);
  	for(int i=1;i<=17;i++)w[i]=i*i;
  	while(1)
	{
		int n;cin>>n;
		if(n<=0)break;
		memset(f,0,sizeof(f));
	  	f[0][0]=1;
	  	for(int i=1;i<=17;i++)
	  	{
	  		for(int j=0;j<=n;j++)f[i&1][j]=0;
	  		for(int k=0;k*w[i]<=n;k++)//当前种类硬币选几个 
	  			for(int x=0;x+k*w[i]<=n;x++)
	  				f[i&1][x+k*w[i]]+=f[(i-1)&1][x];
					  //cout<<i<<" "<<x<<" "<<k<<" "<<x+k*w[i]<<"  - -   "<<f[i&1][x+k*w[i]]<<"   - > "<<f[(i-1)&1][x]<<endl;;
		}
		cout<<f[17&1][n]<<endl;
	}
	return 0;
}

 

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