delete pics to save space

history_source/信息学奥赛一本通/2.8.5.cpp

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+#include<iostream>
+#define maxn 40 
+using namespace std;
+struct Bfs
+{
+	int x,y,step;
+};
+int dx[4]={0,0,-1,1},
+	dy[4]={-1,1,0,0};
+int y,x;
+Bfs bfs[maxn*maxn+100];
+char Map[maxn+1][maxn+1];
+bool che(int xx,int yy)
+{
+	if(xx<0||xx>=x) return 0;
+	if(yy<0||yy>=y) return 0;
+	if(Map[xx][yy]=='#') return 0;
+	return 1;
+}
+int main()
+{
+	cin>>y>>x;
+	for(int i=0;i<y;i++)
+		for(int j=0;j<x;j++)
+			cin>>Map[j][i];
+	int front=0,tail=0;
+	Bfs li;
+	li.x=li.y=0;
+	li.step=1;
+	bfs[tail++]=li;
+	while(tail-front>0)
+	{
+		for(int i=0;i<4;i++)
+		{
+			if(che(bfs[front].x+dx[i],bfs[front].y+dy[i]))
+			{
+				bfs[tail++]=bfs[front];
+				bfs[tail-1].x+=dx[i];
+				bfs[tail-1].y+=dy[i];
+				bfs[tail-1].step++;
+				if(bfs[tail-1].x==x-1&&bfs[tail-1].y==y-1)
+				{
+					cout<<bfs[tail-1].step<<endl;
+					return 0;
+				}
+				Map[bfs[front].x+dx[i]][bfs[front].y+dy[i]]='#';
+			}
+		}
+		front++;
+	}
+	return 0;
+}