UVA 11384 Help is needed for Dexter

F - Help is needed for Dexter

Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu

Submit Status Practice UVA 11384

Description

Help is needed for Dexter

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

 

Problemsetter: Md. Mahbubul Hasan

timmu 

代码是很简单，关键是看懂这道题然后总结规律.:1，主要是判断1~N个数中，任意选取几个数，然后再减去一个特殊的数，使用最少的次数使其都减少到0；例如1~2先选减去1再选1减去1则两次减为0；1~6则是选4,5,6减去4，为1，2,3,0,1,2,3 则6比3多了一个；

一次类推，可以看出1~n中一次是1个1两个2,2*2个3，2^3个4,2^4个5,2^5个6

2:以贪心的思想可以看出一次去取一半则可以的出总的值；

3：依次除以二，看次数。

代码：

代码：#include <stdio.h>int main(){int n;while(~scanf("%d",&n)){    int t=0;    while(n)    {        t++;        n/=2;    }    printf("%d\n",t);}    return 0;}