SJTU OJ 3008 Maze
第一次写关于bfs遍历图的题目,整理一下。
用队列存储可行的结点,pass[][]存储是否走过。
我的代码如下:
#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;
int n, m, x1, y1, x2, y2;
char arr[105][105];
bool pass[105][105] = {false};
int xx[4]={1,0,0,-1};//下、右、左、上
int yy[4]={0,1,-1,0};
int re = -1;
struct node{
int x;
int y;
int len;
};
queue<node> q;
void bfs(){
node s;
s.x = x1;
s.y = y1;
s.len = 0;
q.push(s);
pass[x1][y1] = true;
while(!q.empty())
{
node now=q.front();
q.pop();
for(int i=0;i<4;++i)
{
if (i==0 || i==3){
if (arr[now.x][now.y] == '-') continue;
}
if (i==1 || i==2){
if (arr[now.x][now.y] == '|') continue;
}
node New;
New.x = now.x+xx[i];
New.y = now.y+yy[i];
New.len = now.len+1;
if(New.x<1||New.y<1||New.x>n||New.y>m||pass[New.x][New.y]||arr[New.x][New.y]=='*')
continue;
if (i==0 || i==3){
if (arr[New.x][New.y]=='-') continue;
}
if (i==1 || i==2){
if (arr[New.x][New.y]=='|') continue;
}
q.push(New);
pass[New.x][New.y] = true;
if(New.x==x2 && New.y==y2){
re = New.len;
return;
}
}
}
return;
}
int main(){
cin >> n >> m >> x1 >> y1 >> x2 >> y2;
char tmp;
for (int i=1; i<=n; i++){
for (int j=1; j<=m; j++){
cin >> arr[i][j];
}
}
bfs();
cout << re << endl;
return 0;
}