AYIT暑假集训大一第一周周六赛 F - 全减为1的次数

Description

全减为1的次数

Time Limit: 3 Second

 

Dexter is tired of Dee Dee. So he decided to keep Dee Dee busy in a game. The game he planned for her is quite easy to play but not easy to win at least not for Dee Dee. But Dexter does not have time to spend on this silly task, so he wants your help.

 

There will be a button, when it will be pushed a random number N will be chosen by computer. Then on screen there will be numbers from 1 to N. Dee Dee can choose any number of numbers from the numbers on the screen, and then she will command computer to subtract a positive number chosen by her (not necessarily on screen) from the selected numbers. Her objective will be to make all the numbers 0.

 

For example if N = 3, then on screen there will be 3 numbers on screen: 1, 2, 3. Say she now selects 1 and 2. Commands to subtract 1, then the numbers on the screen will be: 0, 1, 3. Then she selects 1 and 3 and commands to subtract 1. Now the numbers are 0, 0, 2. Now she subtracts 2 from 2 and all the numbers become 0.

 

Dexter is not so dumb to understand that this can be done very easily, so to make a twist he will give a limit L for each N and surely L will be as minimum as possible so that it is still possible to win within L moves. But Dexter does not have time to think how to determine L for each N, so he asks you to write a code which will take N as input and give L as output.

 

Input and Output:

Input consists of several lines each with N such that 1 ≤ N ≤ 1,000,000,000. Input will be terminated by end of file. For each N output L in separate lines.

 

SAMPLE INPUT	OUTPUT FOR SAMPLE INPUT
1 2 3	1 2 2

 

分析

题意：帮助找到最少的次数，就是从那个数中任意选取几个数减去任意一个数，直到所有的数都为0

又是一个规律题，需要你的一次又一次推导，其实也是二分查找，在训练指南的26页

主要公式就是f(a)=f(a/2)+1,y一直递归n==1;

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#include<stdio.h>
int main()
{
    int i,n;
    while(scanf("%d",&n)!=EOF)
    {
for(i=0;n!=0;i++)
    n/=2;
    printf("%d\n",i);
    }
    return 0;
}