You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
81 lines
1.5 KiB
81 lines
1.5 KiB
#include<bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
const int N = 110;
|
|
#define x first
|
|
#define y second
|
|
typedef pair<int, int> PII;
|
|
int a[N][N];
|
|
int dx[] = {-1, 1, 0, 0};
|
|
int dy[] = {0, 0, -1, 1};
|
|
|
|
int n, m, Max;
|
|
vector<PII> s;
|
|
|
|
/**
|
|
测试数据
|
|
4 4
|
|
BLQB
|
|
BBQS
|
|
SBQL
|
|
QQQQ
|
|
|
|
输出
|
|
2
|
|
|
|
3 3
|
|
LSB
|
|
QBQ
|
|
BSL
|
|
|
|
输出
|
|
-1
|
|
*/
|
|
|
|
/**
|
|
* 功能：深度优先搜索
|
|
* @param x 横坐标
|
|
* @param y 纵坐标
|
|
* @param step 步数
|
|
*/
|
|
void dfs(int x, int y, int step) {
|
|
//如果死循环，一直
|
|
if (step > n * m) {
|
|
cout << -1 << endl;
|
|
exit(0);
|
|
}
|
|
//更新步数
|
|
Max = max(Max, step);
|
|
//4个方向
|
|
for (int i = 0; i <= 3; i++) {
|
|
int tx = x + dx[i];
|
|
int ty = y + dy[i];
|
|
//如果出界
|
|
if (tx < 1 || tx > n || ty < 1 || ty > m) continue;
|
|
//下一步与期望值对比
|
|
if (a[tx][ty] == a[x][y] + 1 || (a[tx][ty] == 1 && a[x][y] == 4))
|
|
dfs(tx, ty, step + 1);
|
|
}
|
|
}
|
|
|
|
int main() {
|
|
cin >> n >> m;
|
|
for (int i = 1; i <= n; i++)
|
|
for (int j = 1; j <= m; j++) {
|
|
char x;
|
|
cin >> x;
|
|
//记录起点
|
|
if (x == 'L')
|
|
a[i][j] = 1, s.push_back({i, j});
|
|
else if (x == 'Q') a[i][j] = 2;
|
|
else if (x == 'B') a[i][j] = 3;
|
|
else if (x == 'S') a[i][j] = 4;
|
|
}
|
|
//模拟从每个起点开始
|
|
for (int i = 0; i < s.size(); i++)
|
|
dfs(s[i].x, s[i].y, 1);
|
|
|
|
//长度除以4
|
|
cout << Max / 4 << endl;
|
|
return 0;
|
|
} |