第一天 POJ 1753

//1753

#include <iostream>

#define MAX 999999

using namespace std;

char s[4][4];
int cs[16] = {0x13,0x27,78,140,305,626,1252,2248,4880,8992,20032,35968,12544,29184,58368,51200};

int po[16] = {1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768};

int main()

{

    int i,j,value = 0;

    int cmin = MAX;

    char c;

    for(i = 0;i< 16;i++)

    {

        cin >> c;

        if(c == 'b')

            value += (int)po[i];

        else    continue;

    }

    for(i = 0;i< 65536;i++)

    {

        int cou = 0;

        int cvalue = value;

        for(j = 0;j < 16;j++)

            if(i & (int)po[j])

            {

                cou++;

                cvalue ^= cs[j];

            }

        if(cvalue == 0 || cvalue == 65535)

            if(cou < cmin)  cmin = cou;

    }

    if(cmin == MAX) cout << "Impossible";

    else cout<< cmin<< endl;

   return 0;

}

想到了用位运算判断状态，但脑抽的非要转化成二进制（傻的极致是什么）对于枚举还是理解不到位