poj-2229-Sumsets

Sumsets

Time Limit: 2000MS Memory Limit: 200000KTotal Submissions: 12690 Accepted: 5090

Description

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).

Input

A single line with a single integer, N.

Output

The number of ways to represent N as the indicated sum. Due to the potential huge size of this number, print only last 9 digits (in base 10 representation).

Sample Input

7

Sample Output

6

#include<stdio.h>int a[1000005]={0,1,2,2,4,4,6,6};int main(){    int n,i;    for(i=8;i<1000005;i++)        if(i%2==0)        a[i]=(a[i-2]%1000000000+a[i/2]%1000000000)%1000000000;    else a[i]=a[i-1];    while(scanf("%d",&n)!=EOF)        printf("%d\n",a[n]);    return 0;}