POJ 2965 The Pilots Brothers' refrigerator （暴力枚举）

#include<iostream>
#include<cmath>
#include<cstring>
#include<queue>
#include<vector>
#include<cstdio>
#include<algorithm>
#include<map>
#include<set>

#define rep(i,e) for(int i=0;i<(e);i++)
#define rep1(i,e) for(int i=1;i<=(e);i++)
#define repx(i,x,e) for(int i=(x);i<=(e);i++)
#define X first
#define Y second
#define PB push_back
#define MP make_pair
#define mset(var,val) memset(var,val,sizeof(var))
#define scd(a) scanf("%d",&a)
#define scdd(a,b) scanf("%d%d",&a,&b)
#define scddd(a,b,c) scanf("%d%d%d",&a,&b,&c)
#define pd(a) printf("%d\n",a)
#define scl(a) scanf("%lld",&a)
#define scll(a,b) scanf("%lld%lld",&a,&b)
#define sclll(a,b,c) scanf("%lld%lld%lld",&a,&b,&c)
#define IOS ios::sync_with_stdio(false);cin.tie(0)

using namespace std;
typedef long long ll;
template <class T>
void test(T a){cout<<a<<endl;}
template <class T,class T2>
void test(T a,T2 b){cout<<a<<" "<<b<<endl;}
template <class T,class T2,class T3>
void test(T a,T2 b,T3 c){cout<<a<<" "<<b<<" "<<c<<endl;}
template <class T>
inline bool scan_d(T &ret){
    char c;int sgn;
    if(c=getchar(),c==EOF) return 0;
    while(c!=‘-‘&&(c<‘0‘||c>‘9‘)) c=getchar();
    sgn=(c==‘-‘)?-1:1;
    ret=(c==‘-‘)?0:(c-‘0‘);
    while(c=getchar(),c>=‘0‘&&c<=‘9‘) ret = ret*10+(c-‘0‘);
    ret*=sgn;
    return 1;
}
const int N = 1e6+10;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3fll;
const ll mod = 1000000000;
int T;

void testcase(){
    printf("Case %d:",++T);
}

const int MAXN = 5e5+10 ;
const int MAXM = 150;
const double eps = 1e-8;
const double PI = acos(-1.0);
int n;
int g[5][5];
bool f;
vector<pair<int,int> > vec;
bool check(){
    int t = 1;
    for(int i=0;i<4;i++)
        for(int j=0;j<4;j++)
            if(t!=g[i][j])
                return false;
    return true;
}

void flip(int x,int y){
    g[x][y] = 1-g[x][y]; //需要额外再翻转
    for(int i=0;i<4;i++){
        g[x][i]=1-g[x][i];
        g[i][y]=1-g[i][y];
    }
}

void dfs(int x,int y,int state){
    if(state==0){
        f = check();
        if(f){
            cout<<n<<endl;
            for(int i=0;i<n;i++){
                printf("%d %d\n",vec[i].X+1,vec[i].Y+1);
            }
        }
        return;
    }
    if(f||y>3) return;
    flip(x,y);
    vec.PB(MP(x,y));
    if(x<3) dfs(x+1,y,state-1);
    else dfs(0,y+1,state-1);
    flip(x,y);
    vec.pop_back();
    if(x<3) dfs(x+1,y,state);
    else dfs(0,y+1,state);
    return;
}
void work(){
    char s[6];
    f=false;
    vec.clear();
    for(int i=0;i<4;i++){
        scanf("%s",s);
        for(int j=0;j<4;j++){
            if(s[j]==‘+‘) g[i][j]=0;
            else g[i][j]=1;
        }
    }

    for(n=1;n<=16;n++){
        dfs(0,0,n);
        if(f) break;
    }
    return;
}
int main() {
#ifdef LOCAL
    freopen("in.txt","r",stdin);
#endif // LOCAL
//    init();
    work();
    return 0;
}