hdu 1851 A Simple Game SG定理

#include <cstdio>#include <cstring>#include <cmath>#include <map>#include <queue>#include <stack>#include <iostream>#include <algorithm>using namespace std;const int maxn=22;int sg[maxn][maxn],vis[maxn];void init(){    int i,j,k;    for(k=1;k<=20;k++)    {        sg[k][0]=0;        for(i=1;i<=20;i++)        {            memset(vis,0,sizeof(vis));            for(j=1;j<=min(i,k);j++)                vis[sg[k][i-j]]=1;            for(j=0;;j++)if(!vis[j]){sg[k][i]=j;break;}        }    }}int main(){    int n,T;    init();    cin>>T;    while(T--)    {        cin>>n;        int ans=0,a,b,i;        for(i=0;i<n;i++)        {            cin>>a>>b;            ans^=sg[b][a];        }        if(ans==0)cout<<"Yes"<<endl;        else cout<<"No"<<endl;    }    return 0;}/*    简单博弈(组合游戏)    裸的SG定理*/