POJ 2386 Lake Counting

#include <iostream>
#include <cstdio>
#include <cstring>
#define REP(i, s, n) for(int i = s; i <= n; i ++)
#define REP_(i, s, n) for(int i = n; i >= s; i --)
#define MAX_N 100 + 10

using namespace std;

bool map[MAX_N][MAX_N];
int n, m, ans = 0;
char ch;
int dx[9] = {0, -1, -1, -1, 0, 0, 1, 1, 1},
    dy[9] = {0, -1, 0, 1, -1, 1, -1, 0, 1};

void dfs(int x, int y){
    REP(i, 1, 8){
        if(x + dx[i] > 0 && x + dx[i] <= n && y + dy[i] > 0 && y + dy[i] <= m && map[x + dx[i]][y + dy[i]])
            map[x + dx[i]][y + dy[i]] = 0, dfs(x + dx[i], y + dy[i]);
    }
}        
    
int main(){
    scanf("%d%d", &n, &m);getchar();
    REP(i, 1, n){
        REP(j, 1, m) scanf("%c", &ch),
        map[i][j] = (ch == ‘W‘ ? 1 : 0);
        getchar();
    }
    
    REP(i, 1, n) REP(j, 1, m){
        if(map[i][j]) dfs(i, j), ans ++;
    }
    printf("%d\n", ans);
    return 0;
}