vector<pair<int,int>> transferDir{{0,1},
								  {0,-1},
								  {1,0},
								  {-1,0}};

using p=pair<int,int>;
int INF=10000000;

//开始点为's',终点为'd',障碍物为'#',其余均为'*'
int MinStepToDestin(vector<vector<char>> cmap,int startX,int startY,int desX,int desY){
	int M=cmap.size();
	int N=cmap.at(0).size();


	int step[M][N];
	for (int i = 0; i !=M; ++i) {
		for (int j = 0; j !=N; ++j) {
			step[i][j]=INF;
		}
	}
	step[startX][startY]=0;
	queue<p> que;
	que.push(p{startX,startY});
	while(que.size())
	{
		auto curPos=que.front();
		que.pop();
		if(curPos.first==desX&&curPos.second==desY) break;
		for (decltype(transferDir.size()) i = 0; i !=transferDir.size(); ++i) {
			p newPos(curPos.first+transferDir.at(i).first,curPos.second+transferDir.at(i).second);
			if(newPos.first>=0&&newPos.first<N&&newPos.second>=0&&newPos.second<M&& cmap.at(newPos.first).at(newPos.second)!='#' && step[newPos.first][newPos.second]==INF)
			{
				que.push(newPos);
				step[newPos.first][newPos.second]=step[curPos.first][curPos.second]+1;
			}
		}
	}
	return step[desX][desY];

}