uva 572 - Oil Deposits 입문 고전 II 제6 장 데이터 구조 기초 예제 6 - 12

#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;

char s[110][110];
int  vis[110][110];
int M,N,cnt;

void dfs(int i,int j){
    vis[i][j]=1;
    for(int a=-1;a<=1;a++){
        for(int b=-1;b<=1;b++){
            if(a!=0 || b!=0){
                if(s[i+a][j+b]=='@' && vis[i+a][j+b]==0)
                    dfs(i+a,j+b);
            }
        }
    }
}
int main(){
    while(cin >> M >> N){
        if(M==0&&N==0) break;
        for(int i=0;i<M;i++)
            scanf("%s",&s[i]);

        memset(vis,0,sizeof(vis));
        cnt=0;
        for(int i=0;i<M;i++){
            for(int j=0;j<N;j++){
                if(s[i][j]=='@' && vis[i][j]==0) {
                    cnt++;
                    dfs(i,j);
                }
            }
        }

        cout << cnt << endl;
    }
    return 0;
}

// UVa572 Oil Deposits
// Rujia Liu
//   ：        ，    @        
#include<cstdio>
#include<cstring>
const int maxn = 100 + 5;

char pic[maxn][maxn];
int m, n, idx[maxn][maxn];

void dfs(int r, int c, int id) {
  if(r < 0 || r >= m || c < 0 || c >= n) return;
  if(idx[r][c] > 0 || pic[r][c] != '@') return;
  idx[r][c] = id;
  for(int dr = -1; dr <= 1; dr++)
    for(int dc = -1; dc <= 1; dc++)
      if(dr != 0 || dc != 0) dfs(r+dr, c+dc, id);
}

int main() {
  while(scanf("%d%d", &m, &n) == 2 && m && n) {
    for(int i = 0; i < m; i++) scanf("%s", pic[i]);
    memset(idx, 0, sizeof(idx));
    int cnt = 0;
    for(int i = 0; i < m; i++)
      for(int j = 0; j < n; j++)
        if(idx[i][j] == 0 && pic[i][j] == '@') dfs(i, j, ++cnt);
    printf("%d
", cnt);
  }
  return 0;
}