[博弈论] cf317 D Game with Powers

[博弈论] cf317 D Game with Powers

@(ACM题目)[博弈论]

#include<iostream>#include<cstdio>#include <cstring>#include<cmath>#include<cstdlib>#include<climits>#include<algorithm>#include<vector>#include<map>#include<set>#include<list>#include<stack>using namespace std;typedef long long LL;/*const int maxn = 1e9+1e8;char sg[maxn];int getsg(int S){    if(sg[S] != -1) return sg[S];    bool vis[31] = {0};    for(int i = 1; i <= 30; i++)        if(S&(1<<(i-1)))        {            int tmp = S;            for(int j = i; j <= 30; j += i)            {                if(S&(1<<(j-1))) tmp -= 1<<(j-1);            }            vis[getsg(tmp)] = 1;        }    for(int i = 0; i <= 30; i++)        if(!vis[i]) return sg[S] = i;}int main(){    memset(sg, -1, sizeof sg);    sg[0] = 0;    getsg((1<<29)-1);    for(int i = 0; i < 30; i++) cout<<(int)sg[(1<<i)-1]<<",";    return 0;}*/const int maxn = 1e5;int sg[] = {0,1,2,1,4,3,2,1,5,6,2,1,8,7,5,9,8,7,3,4,7,4,2,1,10,9,3,6,11,12};bool vis[maxn] = {0};int main(){    int n, m; cin>>n;    if(n==1) return puts("Vasya"), 0;    m = sqrt(n+0.5);    int res = sg[1];    int dif = 0;    for(int i = 2; i <= m; i++)        if(!vis[i])        {            int k = 0;            for(LL j = i; j <= n; j *= i)            {                if(j <= m) vis[j] = true;                else dif++;                k++;            }            res ^= sg[k];        }    if((n-m-dif)&1) res ^= sg[1];    puts(res?"Vasya":"Petya");    return 0;}