CodeForces Gym 100735C BFS

就是一个迷宫，然后A可以自己选择去走，但是卫士在A走后会根据A的位置去走，问A能不能拿到那个护身符，假如A拿到后下一步就被卫士干死，也是认为他不能拿到的

就BFS让A走，然后卫士就根据A去模拟就行，状态记录就是walk[ra][ca][rg][cg]，表示 A和卫士各自在的位置，然后就BFS跑就行，只是挺烦的，就错了一个地方，&&改成||就能AC，然后以为自己错误很多就没去查，，，，简直智障

#include <cstdio>
#include <cstring>
#include <vector>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
using namespace std;
const int dx[4] = { -1, 1, 0, 0 };//上下左右
const int dy[4] = { 0, 0, -1, 1 };
struct Node
{
int ra, ca, rg, cg, cnt;
Node() : ra(0), ca(0), rg(0), cg(0), cnt(0) {}
Node(int ra, int ca, int rg, int cg, int cnt)
{
this->ra = ra; this->ca = ca;
this->rg = rg; this->cg = cg;
this->cnt = cnt;
}
};
int N, M;
char grid[30][30];
bool walk[30][30][30][30];
int main()
{
//freopen("input.txt", "r", stdin);
scanf("%d%d", &N, &M);
for (int i = 0; i < N; ++i)
scanf("%s", grid[i]);
Node st;
for (int i = 0; i < N; ++i)
{
for (int j = 0; j < M; ++j)
{
if (grid[i][j] == 'A')
{
st.ra = i; st.ca = j;
grid[i][j] = '.';
}
else if (grid[i][j] == 'G')
{
st.rg = i; st.cg = j;
grid[i][j] = '.';
}
}
}
st.cnt = 0;
/*printf("N %d M %d\n", N, M);
for (int i = 0; i < N; ++i)
printf("%s\n", grid[i]);*/
//printf("ra %d ca %d rg %d cg %d\n", st.ra, st.ca, st.rg, st.cg);
walk[st.ra][st.ca][st.rg][st.cg] = true;
queue<Node> Q;
Q.push(st);
Node t;
int r1, c1, r2, c2;
int ans = -1;
while (!Q.empty())
{
t = Q.front();
Q.pop();
if (grid[t.ra][t.ca] == 'P')
{
ans = t.cnt;
break;
}
for (int i = 0; i < 4; ++i)
{
r1 = t.ra + dx[i];
c1 = t.ca + dy[i];
//printf("a %d %d  %c\n", r1, c1, grid[r1][c1]);
//printf("rg %d cg %d\n", t.rg, t.cg);
if (r1 >= 0 && r1 < N&&c1 >= 0 && c1 < M&&grid[r1][c1] != 'X' && (r1 != t.rg || c1 != t.cg))
{
//printf("a go %d %d\n", r1, c1);
bool guard = false;
if (t.cg < c1)
{
c2 = t.cg + 1; r2 = t.rg;
if (c2 == c1&&r2 == r1)
continue;
if (grid[r2][c2] != 'X')
{
guard = true;
}
}
else if (t.cg > c1)
{
c2 = t.cg - 1; r2 = t.rg;
if (c2 == c1&&r2 == r1)
continue;
if (grid[r2][c2] != 'X')
{
guard = true;
}
}
if (!guard)
{
if (t.rg < r1)
{
r2 = t.rg + 1; c2 = t.cg;
if (c2 == c1&&r2 == r1)
continue;
if (grid[r2][c2] != 'X')
{
guard = true;
}
}
else if (t.rg>r1)
{
r2 = t.rg - 1; c2 = t.cg;
if (c2 == c1&&r2 == r1)
continue;
if (grid[r2][c2] != 'X')
{
guard = true;
}
}
}
if (guard == false)//guard下一步是野兽，所以不能走
{
r2 = t.rg; c2 = t.cg;
}
if (!walk[r1][c1][r2][c2])
{
//printf("%d %d %d %d\n", r1, c1, r2, c2);
Q.push(Node(r1, c1, r2, c2, t.cnt + 1));
walk[r1][c1][r2][c2] = true;
}
}
}
if (ans > -1)
break;
}
printf("%d\n", ans);
//system("pause");
//while (1);
return 0;
}