Luogu3855 [TJOI2008]Binary Land (BFS)

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int  a = (b); a <= (c); ++ a)
#define nR(a,b,c) for(register int  a = (b); a >= (c); -- a)
#define Max(a,b) ((a) > (b) ? (a) : (b))
#define Min(a,b) ((a) < (b) ? (a) : (b))
#define Fill(a,b) memset(a, b, sizeof(a))
#define Swap(a,b) a^=b^=a^=b
#define ll long long
#define ON_DEBUG

#ifdef ON_DEBUG

#define D_e_Line printf("

----------

")
#define D_e(x)  cout << #x << " = " << x << endl
#define Pause() system("pause")

#else

#define D_e_Line ;

#endif

struct ios{
    template<typename ATP>ios& operator >> (ATP &x){
        x = 0; int f = 1; char c;
        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-')  f = -1;
        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
        x*= f;
        return *this;
    }
}io;
using namespace std;

#define stone 2
#define spider 3
#define endPlace 9

const int N = 37;

int n, m;

struct MAP{
	int x_1, y_1, x_2, y_2, step;
}u, v;

#include<queue>

queue<MAP>q;

int mp[N][N];

int ans = 0x3f3f3f3f;

int walk_1[4][2]={{1,0},{0,1},{-1,0},{0,-1}};
int walk_2[4][2]={{1,0},{0,-1},{-1,0},{0,1}};

int vis[N][N][N][N];

inline void BFS(){
	vis[u.x_1][u.y_1][u.x_2][u.y_2] = true;
	q.push(u);
	while(!q.empty()){
		u = q.front();
		q.pop();
		
		if(mp[u.x_1][u.y_1] == endPlace && mp[u.x_2][u.y_2] == endPlace){
			ans = u.step;
			return;	
		}
		
		R(i,0,3){
			v.x_1 = u.x_1 + walk_1[i][0];
			v.y_1 = u.y_1 + walk_1[i][1];
			v.x_2 = u.x_2 + walk_2[i][0];
			v.y_2 = u.y_2 + walk_2[i][1];
			v.step = u.step + 1;
			if(v.x_1 < 1 || v.x_2 < 1 || v.y_1 < 1 || v.y_2 < 1 || v.x_1 > n || v.x_2 > n || v.y_1 > m || v.y_2 > m) continue;
	        if(mp[v.x_1][v.y_1] == stone) v.x_1 = u.x_1, v.y_1 = u.y_1;
	        if(mp[v.x_2][v.y_2] == stone) v.x_2 = u.x_2, v.y_2 = u.y_2;
	        if(mp[v.x_1][v.y_1] == spider || mp[v.x_2][v.y_2] == spider) continue;
	        if(vis[v.x_1][v.y_1][v.x_2][v.y_2]) continue;
	        vis[v.x_1][v.y_1][v.x_2][v.y_2] = 1;
			q.push(v);
	 	}
	}

}

int st[2][2];
int main(){
	io >> n >> m;
	R(i,1,n){
		char str[57];
		scanf("%s", str + 1);
		R(j,1,m){
			switch(str[j]){
				case '#' :{
					mp[i][j] = stone;
					break;
				}
				case 'X' :{
					mp[i][j] = spider;
					break;
				}
				case 'T' :{
					mp[i][j] = endPlace;
					break;
				}
				case 'G' :{
					mp[i][j] = 7;
					st[0][0] = i, st[0][1] = j;
					break;
				}
				case 'M' :{
					mp[i][j] = 8;
					st[1][0] = i, st[1][1] = j;
					break;
				}
				case '.' :{
					mp[i][j] = 1;
					break;
				}
			}
		}
	}
	
	
	
	u = (MAP){st[0][0], st[0][1], st[1][0], st[1][1], 0};
	
	BFS();
	
	if(ans == 0x3f3f3f3f){
		printf("no");
	}
	else{
		printf("%d", ans);
	}
	
	return 0;
}