POJ 2368 Buttons

题目链接：http://poj.org/problem?id=2368

Bash game (巴什博弈）：当K是（L+1）的倍数时可以确保second player赢。所以这道题要找的就是在K的因子中有没有大于2的因子。代码如下：

 #include <iostream>
 #include <math.h>
 #include <stdio.h>
 #include <cstdio>
 #include <algorithm>
 #include <string.h>
 #include <string>
 #include <sstream>
 #include <cstring>
 #include <queue>
 #include <vector>
 #include <functional>
 #include <cmath>
 #include <set>
 #define SCF(a) scanf("%d", &a)
 #define IN(a) cin>>a
 #define FOR(i, a, b) for(int i=a;i<b;i++)
 #define Infinity 999999999
 #define NInfinity -999999999
 #define PI 3.14159265358979323846
 typedef long long Int;
 using namespace std;

 int main()
 {
     int K;
     int a;
     int factor[];
     while (SCF(K) != EOF)
     {
         int len = ;
         for (a = ; a*a <= K; a++)
         {
             if (K % a == )
             {
                 factor[len++] = a;
                 factor[len++] = K / a;
             }
         }
         sort(factor, factor + len);
         bool found = false;
         FOR(i, , len)
         {
             if (factor[i] > )
             {
                 printf("%d\n", factor[i]-);
                 found = true;
                 break;
             }
         }
         if (!found)
             printf("0\n");
     }
     return ;
 }