[数据结构与算法]【POJ】1562 Oil Deposits

可以采用DFS的思想，对于每个油田判断其周围8个位置是否有油田，一直递归下去，然后计数即可：

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

using namespace std;

const int N = 100 + 10;

int m, n, num;
char matrix[N][N];
bool oil[N][N];
int pos[8][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}, {1, 1}, {-1, 1}, {1, -1}, {-1, -1}};

void dfs(int x, int y){
    for(int i = 0; i < 8; i ++ ){
        int nx = x + pos[i][0];
        int ny = y + pos[i][1];
        if(nx < 0 || nx >= m || ny < 0 || ny >= n || oil[nx][ny] || matrix[nx][ny] == '*') continue;
        oil[nx][ny] = true;
        dfs(nx, ny);
    }
}

int main(){
    while(scanf("%d%d", &m, &n) != EOF && m){
        for(int i = 0; i < m; i ++ ){
            scanf("%s", &matrix[i]);
        }
        memset(oil, false, sizeof(oil));
        num = 0;
        for(int i = 0; i < m; i ++ ){
            for(int j = 0; j < n; j ++ ){
                if(matrix[i][j] == '@' && !oil[i][j]){
                    oil[i][j] = true;
                    num++;
                    dfs(i, j);
                }
            }
        }
        printf("%d\n", num);
    }
    return 0;
}