Gym

Problem H. Headshot
Input file: headshot.in
Output file: headshot.out
You have a revolver gun with a cylinder that has n chambers. Chambers are located in a circle on a
cylinder. Each chamber can be empty or can contain a round. One chamber is aligned with the gun’
barrel. When trigger of the gun is pulled, the gun’s cylinder rotates, aligning the next chamber with the
barrel, hammer strikes the round, making a shot by firing a bullet through the barrel. If the chamber is
empty when the hammer strikes it, then there is no shot but just a “click”.
You have found a use for this gun. You are playing Russian Roulette with your friend. Your friend load
rounds into some chambers, randomly rotates the cylinder, aligning a random chamber with a gun’
barrel, puts the gun to his head and pulls the trigger. You hear “click” and nothing else — the chamber
was empty and the gun did not shoot.
Now it is your turn to put the gun to your head and pull the trigger. You have a choice. You can eithe
pull the trigger right away or you can randomly rotate the gun’s cylinder and then pull the trigger. What
should you choose to maximize the chances of your survival?
Input
The input file contains a single line with a string of n digits “0” and “1” (2 ≤ n ≤ 100). This line o
digits represents the pattern of rounds that were loaded into the gun’s chambers. “0” represent an empty
chamber, “1” represent a loaded one. In this representation, when cylinder rotates before a shot, the
next chamber to the right gets aligned with the barrel for a shot. Since the chambers are actually located
on a circle, the first chamber in this string follows the last one. There is at least one “0” in this string.
Output
Write to the output file one of the following words (without quotes):
* “SHOOT” — if pulling the trigger right away makes you less likely to be actually shot in the head
with the bullet (more likely that the chamber will be empty).
* “ROTATE” — if randomly rotating the cylinder before pulling the trigger makes you less likely to be
actually shot in the head with the bullet (more likely that the chamber will be empty).
* “EQUAL” — if both of the above choices are equal in terms of probability of being shot.
Sample input and output
headshot.in headshot.out
0011 EQUAL
0111 ROTATE

000111 SHOOT

题意：两个枪手之间的游戏，告诉你枪内子弹的情况，第一个人转了一下开枪，没有死，问第二个人是直接开枪活下来的概率大还是转一下活下来的概率大

思路：统计一下0,00,01的个数算一下概率就可以了，注意一点，收尾是相连的

ac代码：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
char a[105];
int main()
{
    freopen("headshot.in","r",stdin);
    freopen("headshot.out","w",stdout);
    while(gets(a))
    {
      int len=strlen(a);
      double p,q;
      double sum=0;
      for(int i=0;i<len;i++)
      {
          if(a[i]=='0')
          sum++;
      }
      double k1=0,k2=0;
      for(int i=0;i<len-1;i++)
      {
          if(a[i]=='0'&&a[i+1]=='1')
          k1++;
          if(a[i]=='0'&&a[i+1]=='0')
          k2++;
      }
      if(a[len-1]=='0'&&a[0]=='0')
      k2++;
      if(a[len-1]=='0'&&a[0]=='1')
      k1++;
      if(sum/len==k2/(k1+k2))
      cout<<"EQUAL"<<endl;
      if(sum/len>k2/(k1+k2))
      cout<<"ROTATE"<<endl;
      if(sum/len<k2/(k1+k2))
      cout<<"SHOOT"<<endl;
    }
    return 0;
}