URAL1079：Maximum

http://acm.timus.ru/problem.aspx?space=1&num=1079

Consider the sequence of numbers a_i, i = 0, 1, 2, …, which satisfies the following requirements:

• a₀ = 0
• a₁ = 1
• a_2i = a_i
• a_2i+1 = a_i + a_i+1

for every i = 1, 2, 3, … .

Write a program which for a given value of n finds the largest number among the numbers a ₀, a ₁, …, a_n.

Input

You are given several test cases (not more than 10). Each test case is a line containing an integer n (1 ≤  n ≤ 99 999). The last line of input contains 0.

Output

For every n in the input write the corresponding maximum value found.

Sample

input	output
5100	34

 

 

水题，按照公式打表即可

 

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;

__int64 a[1000000];
__int64 hash[1000000];

int main()
{
    int i,j,n;
    __int64 maxn;
    a[0] = 0;
    hash[0] = 0;
    a[1] = 1;
    hash[1] = 1;
    maxn = 1;
    for(i = 2; i<=999999; i++)
    {
        if(i%2)
        {
            j = (i-1)/2;
            a[i] = a[j]+a[j+1];
        }
        else
            a[i] = a[i/2];
        if(a[i]>maxn)
            maxn = a[i];
        hash[i] = maxn;
    }
    while(~scanf("%d",&n) && n)
    {
        printf("%I64d\n",hash[n]);
    }


    return 0;
}