标签：des style blog http io color ar os 使用
Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer power of 2. Here are the possible sets of numbers that sum to 7: 1) 1+1+1+1+1+1+1 2) 1+1+1+1+1+2 3) 1+1+1+2+2 4) 1+1+1+4 5) 1+2+2+2 6) 1+2+4 Help FJ count all possible representations for a given integer N (1 <= N <= 1,000,000).
给出一个N(1≤N≤10^6)，使用一些2的若干次幂的数相加来求之．问有多少种方法
一个整数N.
方法数．这个数可能很大，请输出其在十进制下的最后9位．
这道题很明显是可以递推的。Orz f[i]=f[i-1]+(i&1==0?f[i/2]:0)
1 /*Author:WNJXYK*/ 2 #include<cstdio> 3 using namespace std; 4 5 const int N=1000005; 6 int f[N], n; 7 8 int main() { 9 scanf("%d",&n); 10 f[1]=1; 11 for(int i=2;i<=n;i++) { 12 f[i]=f[i-1]; 13 if(!(i&1)) f[i]+=f[i>>1]; 14 f[i]%=1000000000; 15 } 16 printf("%d\n",f[n]); 17 return 0; 18 }
BZOJ 1677: [Usaco2005 Jan]Sumsets 求和
标签：des style blog http io color ar os 使用
原文地址：http://www.cnblogs.com/WNJXYK/p/4072877.html
