hihocoder #1196 : 高斯消元·二

#include
#include
#include
#include
using namespace std;   
#define FOR(i,b,e) for(int i=(b);i<=(e);i++)  
#define FORE(i,b,e) for(int i=(b);i>=(e);i--)  
#define maxnum 503

int n[33][33];
int v[33];
int y[33];
int *pn[33];

int pos[4][2]={{0,1},{1,0},{0,-1},{-1,0}};
int main()
{
#ifdef DEBUG_
    ifstream fin("G:/1.txt");
#define cin fin
#endif
    memset(v,0,sizeof(v));
    memset(n,0,sizeof(n));
    memset(y,0,sizeof(y));
    char state[7];
    FOR(i,0,4){
        cin>>state;
        FOR(j,0,5){
            int num=i*6+j;
            y[num]=(state[j]=='1')?0:1;
            n[num][num]=1;
            pn[num]=n[num];
            if(num%6>0)n[num][num-1]=1;
            if((num+1)%6>0)n[num][num+1]=1;
            if(num-6>=0)n[num][num-6]=1;
            if(num+6<30)n[num][num+6]=1;

        }
    }
    int x=0,row=0;
    for(x=0;x<30;x++,row++){
        if(pn[row][x]==0){
            FOR(j,row+1,29)
                if(pn[j][x]){
                    swap(pn[row],pn[j]);
                    swap(y[row],y[j]);
                    break;
                }
        }
        if(!pn[row][x]){
            row--;
            continue;
        }
        FOR(j,row+1,29){
            if(!pn[j][x])continue;
            FOR(k,0,29){
                pn[j][k]^=pn[row][k];
            }

            y[j]^=y[row];
        }
    }

    x=29;
    row=(row==30)?29:row;
    FORE(i,row,0){
        while(pn[row][x-1]){
            v[x]=1;
            for(int j=i;j>=0;j--){
                if(!pn[j][x])continue;
                y[j]^=y[i];
                pn[j][i]=0;
            }
            x--;
        }
        v[x]=y[x];
        for(int j=i-1;j>=0;j--){
                if(!pn[j][x])continue;
                y[j]^=y[i];
                pn[j][i]=0;
            }
        x--;
    }
    int sum=0;
    FOR(i,0,29)
        sum+=v[i];
    cout<0,29)
        if(v[i])
            cout<6+1<<" "<6+1<cout<return 0;
}