HDU-1398-Square Coins(母函数)
链接:
https://vjudge.net/problem/HDU-1398
题意:
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.
思路:
母函数模板, 枚举平方
代码:
#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<math.h>
#include<vector>
using namespace std;
typedef long long LL;
const int INF = 1e9;
const int MAXN = 300+10;
int c1[MAXN], c2[MAXN];
int n;
void Init()
{
c1[0] = 1;
for (int i = 1;i <= 17;i++)
{
for (int j = 0;j < MAXN;j+=i*i)
{
for (int k = 0;k+j < MAXN;k++)
c2[j+k] += c1[k];
}
for (int j = 0;j < MAXN;j++)
{
c1[j] = c2[j];
c2[j] = 0;
}
}
}
int main()
{
Init();
while(~scanf("%d", &n) && n)
{
printf("%d\n", c1[n]);
}
return 0;
}