【HDOJ】2267 How Many People Can Survive

BFS。

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

#define MAXN 305

typedef struct node_st {
    int x, y;
    node_st() {}
    node_st(int xx, int yy) {
        x = xx; y = yy;
    }
} node_st;

char map[MAXN][MAXN];
bool visit[MAXN][MAXN];
int direct[4][2] = {-1,0,1,0,0,-1,0,1};
int n, m, f, s;

bool getNext(int *x, int *y) {
    for (int i=0; i<n; ++i) {
        for (int j=0; j<m; ++j) {
            if (map[i][j]!='#' && visit[i][j]==false) {
                *x = i;
                *y = j;
                return true;
            }
        }
    }
    return false;
}

void bfs() {
    queue<node_st> que;
    node_st node;
    int ff, ss, x, y;
    bool flg;
    int i;

    f = s = 0;
    memset(visit, false, sizeof(visit));
    while (1) {
        if (!getNext(&x, &y))
            break;
        ff = ss = 0;
        if (map[x][y] == 'o')   ++ff;
        if (map[x][y] == 'v')   ++ss;
        que.push(node_st(x, y));
        visit[x][y] = true;
        flg = false;

        while (!que.empty()) {
            node = que.front();
            que.pop();
            for (i=0; i<4; ++i) {
                x = node.x + direct[i][0];
                y = node.y + direct[i][1];
                if (x<0 || x>=n || y<0 || y>=m) {
                    flg = true;
                    continue;
                }
                if (map[x][y]!='#' && !visit[x][y]) {
                    que.push(node_st(x, y));
                    visit[x][y] = true;
                    if (map[x][y] == 'o')   ++ff;
                    if (map[x][y] == 'v')   ++ss;
                }
            }
        }
        if (!flg) {
            if (ff > ss)    f += ff;
            if (ff < ss)    s += ss;
        }
    }
    printf("%d %d
", f, s);
}

int main() {
    int i;

    while (scanf("%d %d", &n, &m) != EOF) {
        for (i=0; i<n; ++i)
            scanf("%s", map[i]);
        bfs();
    }

    return 0;
}