poj 1753 2965

状态压缩+枚举

#include <iostream>
#include <string>
#include <vector>
#include <cstdlib>
#include <cmath>
#include <map>
#include <algorithm>
#include <list>
#include <ctime>
#include <set>
#include <queue>

using namespace std;
typedef long long ll;

int relation[4][4];
int dx[] = { 1, 0, -1, 0 };
int dy[] = { 0, 1, 0, -1 };
void addone(int x, int y, int& res) {
    if (x < 0 || x >= 4 || y < 0 || y >= 4) {
        return;
    }
    int offset = x * 4 + y;
    res = (res | (1 << offset));

}
int main() {
    string data[4];
    for (int i = 0; i < 4; i++) {
        cin >> data[i];
    }
    int dp, dpori;
    dp = dpori = 0;
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            if (data[i][j] == 'b') {
                addone(i, j, dp);
            }
        }
    }
    dpori = dp;
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            addone(i, j, relation[i][j]);
            for (int k = 0; k < 4; k++) {
                addone(i + dx[k], j + dy[k], relation[i][j]);
            }
        }
    }
    int res = 1000;
    int allstate = (1 << 16) - 1;
    for (int i = 0; i <= allstate; i++) {
        dp = dpori;
        int cun = 0;

        for (int a = 0; a < 4; a++) {
            for (int b = 0; b < 4; b++) {
                int tnum = a * 4 + b;
                if (i & (1 << tnum)) {
                    cun++;
                    dp = dp ^ (relation[a][b]);
                }
            }
        }
        if (0 == dp || allstate == dp) {
            res = min(res, cun);
        }

    }
    if (1000 == res) {
        cout << "Impossible";
        return 0;
    }
    cout << res;
    return 0;
}

#include <iostream>
#include <string>
#include <vector>
#include <cstdlib>
#include <cmath>
#include <map>
#include <algorithm>
#include <list>
#include <ctime>
#include <set>
#include <queue>

using namespace std;
typedef long long ll;

int relation[4][4];
int dx[] = { 1, 0, -1, 0 };
int dy[] = { 0, 1, 0, -1 };
void addone(int x, int y, int& res) {
    if (x < 0 || x >= 4 || y < 0 || y >= 4) {
        return;
    }
    int offset = x * 4 + y;
    res = (res | (1 << offset));

}
int main() {
    string data[4];
/*    string data[4]={"-+--","----","----","-+--"};*/
    for (int i = 0; i < 4; i++) {
        cin >> data[i];
    }
    int dp, dpori;
    dp = dpori = 0;
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            if (data[i][j] == '+') {
                addone(i, j, dp);
            }
        }
    }
    dpori = dp;
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            for (int k = 0; k < 4; k++) {
                addone(i, k, relation[i][j]);
                addone(k, j, relation[i][j]);
            }
        }
    }
    int res = 1000;
    int restag=0;
    int allstate = (1 << 16) - 1;
    for (int i = 0; i <= allstate; i++) {
        dp = dpori;
        int cun = 0;

        for (int a = 0; a < 4; a++) {
            for (int b = 0; b < 4; b++) {
                int tnum = a * 4 + b;
                if (i & (1 << tnum)) {
                    cun++;
                    dp = dp ^ (relation[a][b]);
                }
            }
        }
        if (0 == dp ) {
            if(res>cun){
            res = min(res, cun);
            restag=i;
            }
        }

    }
    if (1000 == res) {
        cout << "Impossible";
        return 0;
    }
    cout << res<<endl;
    for(int i=0;i<16;i++){
        if(restag&(1<<i)){
            int x=i/4;
            int y=i%4;
            cout<<(x+1)<<" "<<(y+1)<<endl;
        }
    }
    return 0;
}