hdu1312 Red and Black

一道裸的 \(bfs\) ，然而还是折腾到我了。

/**
* hdu1312 Red and Black
* bfs
*/
#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;

#define pii pair<int,int>
#define x first
#define y second

const int N = 22;
char mp[N][N];
int dir[][2] = {
    -1, 0,
    0, 1,
    1, 0,
    0, -1
};
int bfs(int sx, int sy)
{
    int ans = 0;
    queue<pii> Q;
    Q.push(pii{sx, sy});
    while (!Q.empty()) {
        pii q = Q.front(); Q.pop();
        ++ans;
        for (int i = 0; i < 4; ++i) {
            int tx = q.x+dir[i][0];
            int ty = q.y+dir[i][1];
            if (mp[tx][ty] != ‘.‘) continue;
            Q.push(pii{tx, ty});
            mp[tx][ty] = ‘#‘;
        }
    }
    return ans;
}
int main()
{
    int n, m;  // n行m列
    int sx, sy;  // ‘@’所在位置
    while (~scanf("%d%d", &m, &n) && (n|m)) {
        for (int j = 1; j <= m; ++j) mp[0][j] = mp[n+1][j] = ‘#‘;
        for (int i = 1; i <= n; ++i) {
            getchar();
            mp[i][0] = mp[i][m+1] = ‘#‘;
            for (int j = 1; j <= m; ++j) {
                mp[i][j] = getchar();
                if (mp[i][j] == ‘@‘) sx = i, sy = j;
            }
        }
/*
        cout << endl;
        for (int i = 0; i <= n+1; ++i) {
            for (int j = 0; j <= m+1; ++j)
                cout << mp[i][j];
            cout << endl;
        }
        cout << endl;
*/
        cout << bfs(sx, sy) << endl;
    }
    // cout << n << ‘ ‘ << m;
    return 0;
}

hdu1312 Red and Black

原文：https://www.cnblogs.com/zbhfz/p/14312229.html