hdu 3980 Paint Chain sg函数

时间:2024-11-28 18:06:20

题目链接

给一个长度为n的环, 两个人轮流涂色, 每次涂m个连续的, 无法继续涂了就输。

 #include<bits/stdc++.h>
using namespace std;
#define pb(x) push_back(x)
#define ll long long
#define mk(x, y) make_pair(x, y)
#define lson l, m, rt<<1
#define mem(a) memset(a, 0, sizeof(a))
#define rson m+1, r, rt<<1|1
#define mem1(a) memset(a, -1, sizeof(a))
#define mem2(a) memset(a, 0x3f, sizeof(a))
#define rep(i, a, n) for(int i = a; i<n; i++)
#define ull unsigned long long
typedef pair<int, int> pll;
const double PI = acos(-1.0);
const double eps = 1e-;
const int mod = 1e9+;
const int inf = ;
const int dir[][] = { {-, }, {, }, {, -}, {, } };
int sg[], m;
int mex(int x) {
if(~sg[x])
return sg[x];
if(x<m)
return sg[x] = ;
int vis[];
mem(vis);
for(int i = ; i<=x-m; i++) {
vis[mex(i)^mex(x-m-i)] = ; //相当于把一堆个数为x的石子分成两堆, 一堆个数为i, 另一堆为x-m-i
}
int i = ;
while() {
if(!vis[i])
return sg[x] = i;
i++;
}
}
int main()
{
int t, n, cnt = ;
cin>>t;
while(t--) {
mem1(sg);
scanf("%d%d", &n, &m);
printf("Case #%d: ", cnt++);
if(n<m) {
puts("abcdxyzk");
continue;
}
sg[n-m] = mex(n-m);
if(!sg[n-m]) {
puts("aekdycoin");
} else {
puts("abcdxyzk");
}
}
return ;
}