HDU1198

这道题DFS,BFS,并查集好像都可以

觉得深搜跟并查集可能会更简单一些

#include "iostream"
#include "algorithm"
#include "memory.h"
#include "cmath"
#include "string"
using namespace std;
#define MAXN 550


char s[15][6] = {
    { "1100" }, {"0110"}, {"1001"}, {"0011"}, {"0101"}, {"1010"}, {"1110"}, {"1101"}, {"1011"}, {"0111"}, {"1111"}
};
int n, m,num;
int fa[MAXN*MAXN];
string a[550];

int find(int x)
{
    if (fa[x] < 0) return x;
    return fa[x] = find(fa[x]);
}

void merge(int a, int b)
{
    int x = find(a);
    int y = find(b);
    if (x < y) {
        fa[x] += fa[y];
        fa[y] = x;
    }
    if (x > y) {
        fa[y] += fa[x];
        fa[x] = y;
    }
}

void judge(int i, int j, int x, int y)
{
    if (y < m && s[a[i][j] - 'A'][2] == '1' && s[a[i][y] - 'A'][0] == '1') 
        merge(i*m + j, i*m + y);
    if (x < n && s[a[i][j] - 'A'][3] == '1' && s[a[x][j] - 'A'][1] == '1')
        merge(i*m + j, x*m + j);
}


void init()
{
    memset(fa,-1,sizeof(fa));
    num = 0;
}

int main()
{
    while (cin >> n >> m) {
        if (n < 1 || m < 1) break;
        init();
        for (int i = 0; i < n; ++i){
            a[i].clear();
            cin >> a[i];
        }
        for (int i = 0; i < n; ++ i)
            for (int j = 0; j < m; ++j) {
                int x = i + 1;
                int y = j + 1; 
                judge(i,j,x,y);
            }
        for (int i = 0; i < n*m; ++i)
            if (fa[i] < 0) num++;
            //cout << fa[i] << " ";
        cout << num << endl;
    }
    return 0;
}