hdu1198 并查集（值得复习）

#include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;

/*
个人感觉本解法非常好， 
*/

char sign[11][5]={"1010","1001","0110","0101","1100","0011",
               "1011","1110","0111","1101","1111"};
int Set[100][100];
char str[100][100];
int n, m;

int Find(int x) {

   return x == Set[x/m][x%m] ? x : Set[x/m][x%m] = Find(Set[x/m][x%m]);
}

void Union(int x, int y) {

    x = Find(x);
    y = Find(y);
    if(x != y) {

        Set[x/m][x%m] = y;
    }
}

void judge(int i, int j) {


    if(j > 0 && sign[str[i][j]-'A'][2] == '1' && sign[str[i][j-1]-'A'][3] == '1') {

        Union(i*m+j, i*m + j-1);
    }
    if(i > 0 && sign[str[i][j]-'A'][0] == '1' && sign[str[i-1][j]-'A'][1] == '1') {

        Union(i*m+j, (i-1)*m+j);
    }
}

int main()
{
    while(scanf("%d%d", &n, &m) != EOF) {

        if(n < 0 && m < 0)
            break;
        for(int i = 0; i < n; i++) {

            scanf("%s", str[i]);
            for(int j = 0; j < m; j++) {

                Set[i][j] = i*m+j;
            }
        }
        for(int i = 0; i < n; i++) {

            for(int j = 0; j < m; j++) {

                judge(i, j);
            }
        }

        int ans = 0;

        for(int i = 0; i < n; i++) {

            for(int j = 0; j < m; j++) {

                if(Set[i][j] == i*m + j)
                    ans++;
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}