Nim

http://poj.org/problem?id=2975

Nim博弈;

求必胜时总数

// File Name: poj2975.cpp// Author: bo_jwolf// Created Time: 2013年10月01日 星期二 21:51:44#include<vector>#include<list>#include<map>#include<set>#include<deque>#include<stack>#include<bitset>#include<algorithm>#include<functional>#include<numeric>#include<utility>#include<sstream>#include<iostream>#include<iomanip>#include<cstdio>#include<cmath>#include<cstdlib>#include<cstring>#include<ctime>using namespace std;const int maxn = 100005;int main(){long long Case, n, ans, sum, num[ maxn ];while( scanf( "%lld", &n ) != EOF && n ){ans = 0;for( long long i = 1; i <= n; ++i ){scanf( "%lld", &num[ i ] );ans ^= num[ i ];}sum = 0 ;for( long long i = 1; i <= n; ++i ){if( ( ans ^ num[ i ] )<= num[ i ] )sum++;}if( ans == 0 )sum = 0 ;printf( "%lld\n", sum );}return 0;}