[hdu1079]简单博弈

题意:两个人玩游戏,给定一个日期,他们轮流选择日期,可以选择当前日期的下一天,如果下一个月也有这一天的话则也可以选择下一个月的这一天。超过某一日期的人输。

思路:以天为状态,则一共有300多万个左右的状态,然后用dp预处理每个状态是必胜态还是必败态。一个状态是必胜态当且仅存在它的一个后继是必败态,一个状态是必败态当且仅当它的所有后继都是必胜态,写成逻辑式则是:state(now)= !state(next1) || !state(next2) || .. || !state(nextn)

由于空间不足,采用一个4位int存年月日,方法是用8个十进制位,高4位存年,中2位存月,低2位存日。

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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;                                                            //
                                                                                    //
/* -------------------------------------------------------------------------------- */
 
const int month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int maxn = 4e6;
 
struct Node {
    int s;
    int gety() { return s / 10000; }
    int getm() { return s / 100 % 100; }
    int getd() { return s % 100; }
    Node(int y = 0, int m = 0, int d = 0) {
        s = y * 10000 + m * 100 + d;
    }
    Node nextm() {
        int y = gety(), m = getm() + 1, d = getd();
        if (m == 12) {
            y ++;
            m = 0;
        }
        return Node(y, m, d);
    }
};
Node state[maxn];
int cnt;
int hsh[102][12][31];
bool dp[maxn];
 
 
bool leap(int y) {
    return y % 4 == 0 && y % 100 != 0 || y % 400 == 0;
}
 
void pre_init() {
    for (int i = 0; i < 102; i ++) {
        for (int j = 0; j < 12; j ++) {
            int M = month[j];
            if (leap(i + 1900) && j == 1) M ++;
            for (int k = 0; k < M; k ++) {
                state[cnt] = Node(i, j, k);
                hsh[i][j][k] = cnt ++;
            }
        }
    }
    for (int i = hsh[101][10][3] + 1; i < cnt; i ++) dp[i] = true;
    for (int i = hsh[101][10][3] - 1; i >= 0; i --) {
        Node S = state[i].nextm();
        int y = S.gety(), m = S.getm(), d = S.getd();
        dp[i] = !dp[i + 1];
        if (hsh[y][m][d]) dp[i] = dp[i] || !dp[hsh[y][m][d]];
    }
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("in.txt""r", stdin);
    //freopen("out.txt", "w", stdout);
#endif // ONLINE_JUDGE
    pre_init();
    int T;
    cin >> T;
    while (T --) {
        int y, m, d;
        scanf("%d%d%d", &y, &m, &d);
        int n = hsh[y - 1900][m - 1][d - 1];
        puts(dp[n]? "YES" "NO");
    }
    return 0;
}
/* ******************************************************************************** */
原文地址:https://www.cnblogs.com/jklongint/p/4700298.html