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[hdu1847]博弈,推理

时间:2015-08-04 00:24:47      阅读:154      评论:0      收藏:0      [点我收藏+]

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题意:一堆石子,有n个,两个人轮流取,每次都只能取2的幂次方个数,不能取的人输

思路:首先0是必败态,2的所有幂次都是必胜态。由于选的数模3只能是1或2,恰好又都是2的幂次,0,、3都为必败态,猜想3的所有倍数也为必败态,证明如下:设状态为x=3k,先手任选一个t,那么(x-t)%3不是1就是2,后手就取(x-t)%3,使得先手面临的状态始终是3的倍数,并且只要先手可以取,那么后手也就可以取,所以3的倍数都是必败态。对于x=3k+p,p=1或2的状态,先手都可以将其变成必败态,即先手取p=x%3即可,因此为必胜态。


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/* ******************************************************************************** */
#include <iostream>                                                                 //
#include <cstdio>                                                                   //
#include <cmath>                                                                    //
#include <cstdlib>                                                                  //
#include <cstring>                                                                  //
#include <vector>                                                                   //
#include <ctime>                                                                    //
#include <deque>                                                                    //
#include <queue>                                                                    //
#include <algorithm>                                                                //
#include <map>                                                                      //
#include <cmath>                                                                    //
using namespace std;                                                                //
                                                                                    //
#define pb push_back                                                                //
#define mp make_pair                                                                //
#define X first                                                                     //
#define Y second                                                                    //
#define all(a) (a).begin(), (a).end()                                               //
#define fillchar(a, x) memset(a, x, sizeof(a))                                      //
                                                                                    //
typedef pair<intint> pii;                                                         //
typedef long long ll;                                                               //
typedef unsigned long long ull;                                                     //
                                                                                    //
#ifndef ONLINE_JUDGE                                                                //
void RI(vector<int>&a,int n){a.resize(n);for(int i=0;i<n;i++)scanf("%d",&a[i]);}    //
void RI(){}void RI(int&X){scanf("%d",&X);}template<typename...R>                    //
void RI(int&f,R&...r){RI(f);RI(r...);}void RI(int*p,int*q){int d=p<q?1:-1;          //
while(p!=q){scanf("%d",p);p+=d;}}void print(){cout<<endl;}template<typename T>      //
void print(const T t){cout<<t<<endl;}template<typename F,typename...R>              //
void print(const F f,const R...r){cout<<f<<", ";print(r...);}template<typename T>   //
void print(T*p, T*q){int d=p<q?1:-1;while(p!=q){cout<<*p<<", ";p+=d;}cout<<endl;}   //
#endif // ONLINE_JUDGE                                                              //
template<typename T>bool umax(T&a, const T&b){return b<=a?false:(a=b,true);}        //
template<typename T>bool umin(T&a, const T&b){return b>=a?false:(a=b,true);}        //
template<typename T>                                                                //
void V2A(T a[],const vector<T>&b){for(int i=0;i<b.size();i++)a[i]=b[i];}            //
template<typename T>                                                                //
void A2V(vector<T>&a,const T b[]){for(int i=0;i<a.size();i++)a[i]=b[i];}            //
                                                                                    //
const double PI = acos(-1.0);                                                       //
const int INF = 1e9 + 7;                                                            //
                                                                                    //
/* -------------------------------------------------------------------------------- */
 
int main() {
#ifndef ONLINE_JUDGE
    freopen("in.txt""r", stdin);
    //freopen("out.txt", "w", stdout);
#endif // ONLINE_JUDGE
    int n;
    while (cin >> n) {
        puts(n % 3? "Kiki" "Cici");
    }
    return 0;
}
/* ******************************************************************************** */

[hdu1847]博弈,推理

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原文地址:http://www.cnblogs.com/jklongint/p/4700715.html

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