CSU 1604: SunnyPig

来源：互联网发布：90后流行网络女歌手编辑：程序博客网时间：2024/06/07 21:08

http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1604

bfs
题意：一只猪要出去，最少要开几扇门，要注意对于不同的门只能朝一个方向打开，而出口的地方，必然有一扇门

#include <iostream> #include <stdio.h> #include <string.h> #include <stack> #include <queue> #include <map> #include <set> #include <vector> #include <math.h> #include <algorithm> using namespace std; #define ls 2*i #define rs 2*i+1 #define up(i,x,y) for(i=x;i<=y;i++) #define down(i,x,y) for(i=x;i>=y;i--) #define mem(a,x) memset(a,x,sizeof(a)) #define w(a) while(a) #define LL long long const double pi = acos(-1.0); #define Len 200005 #define mod 19999997 const int INF = 0x3f3f3f3f; #define exp 1e-8 struct node {     int x,y,door; }; int mat[1000][1000],n,m,t,vis[1000][1000],sx,sy; char str[1005]; int to[5][2]= {0,0,0,1,1,0,0,-1,-1,0}; bool outdoor(int x,int y) {     if(x==0||y==0||x==n-1||y==m-1)         return true;     return false; } bool check(int x,int y) {     if(x<0||y<0||x==n||y==m)         return true;     if(mat[x][y]==-1||vis[x][y])         return true;     return false; } void bfs() {     queue<node> Q;     node a,next;     int i,j;     a.x = sx;     a.y = sy;     a.door = 0;     vis[sx][sy] = 1;     Q.push(a);     while(!Q.empty())     {         a = Q.front();         Q.pop();         if(outdoor(a.x,a.y)&&mat[a.x][a.y]>0)         {             printf("%d\n",a.door);             return ;         }         up(i,1,4)         {             next = a;             next.x+=to[i][0];             next.y+=to[i][1];             if(check(next.x,next.y)) continue;             if(mat[next.x][next.y]>0 && mat[next.x][next.y]!=i) continue;             if(mat[next.x][next.y]>0)             {                 next.door++;                 if(outdoor(next.x,next.y))                 {                     printf("%d\n",next.door);                     return ;                 }             }             vis[next.x][next.y] = 1;             Q.push(next);         }     }     printf("-1\n"); } int main() {     int i,j,k;     scanf("%d",&t);     w(t--)     {         scanf("%d%d\n",&n,&m);         n=2*n+1;         m=2*m+1;         mem(mat,-1);         up(i,0,n-1)         {             gets(str);             up(j,0,m-1)             {                 if(str[j]==' '||str[j]=='*')                     mat[i][j]=0;                 else if(str[j]=='-'||str[j]=='|')                     mat[i][j]=-1;                 else if(str[j]=='E')                     mat[i][j]=1;                 else if(str[j]=='S')                     mat[i][j]=2;                 else if(str[j]=='W')                     mat[i][j]=3;                 else if(str[j]=='N')                     mat[i][j]=4;                 else if(str[j]=='O')                 {                     sx = i;                     sy = j;                     mat[i][j]=0;                 }             }         }         bfs();     }     return 0; }

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