题意:一个整数N划分成几个数的和,问有多少种划分方法
思路:母函数
如果不懂母函数的请看一下链接:
http://blog.youkuaiyun.com/leonharetd/article/details/8922262
然后就是直接模拟多项式相乘
#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
int c1[10006];
int c2[10006];
int main()
{
int n;
while(scanf("%d",&n) != EOF)
{
memset(c1,0,sizeof(c1));
memset(c2,0,sizeof(c2));
c1[0] = 1;
for(int i = 1; i <= n; i++)
{
for(int j = 0; j <= n; j++)
{
for(int k = 0; j+i*k <= n; k++)
{
c2[j+k*i] += c1[j];
}
}
memcpy(c1,c2,sizeof(c2));
memset(c2,0,sizeof(c2));
}
printf("%d\n",c1[n]);
}
return 0;
}