[ZOJ3591] Nim && 博弈+计数

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
#include<map>
#define SF scanf
#define PF printf
#define max(a, b) ((a) < (b) ? (b) : (a))
using namespace std;
typedef long long LL;
const int MAXN = 100000;
int s[MAXN+10], a[MAXN+10], n, S, W;
map <int, int> M;
void Make_a()
{
	int g = S; 
	for (int i=1; i<=n; i++) { 
		a[i] = g;
		if( a[i] == 0 ) { a[i] = g = W; }
		if( g%2 == 0 ) { g = (g/2); }
		else           { g = (g/2) ^ W; }
	}
}
int main()
{
	int T; SF("%d", &T); while(T--) {
		SF("%d%d%d", &n, &S, &W);
		Make_a();
		for(int i = 1; i <= n; i++) s[i] = s[i-1] ^ a[i];
		M.clear();
		M[0] = 1;
		LL Fail = 0;
		for(int i = 1; i <= n; i++) 
		{
			if(M.count(s[i]))
			{
				Fail += M[s[i]];
				M[s[i]]++;
			}
			else M[s[i]] = 1;
		}
		cout << (LL)n * (n + 1) / 2 - Fail << '\n';
	}
}