ACM/ICPC 2018亚洲区预选赛北京赛站网络赛 A.Saving Tang Monk II（优先队列广搜）

#include<bits/stdc++.h>
using namespace std;
const int maxN = ;
const int inf = 1e9 + ;
char G[maxN][maxN];
int times[maxN][maxN][];
int n, m, sx, sy, ex, ey, ans;
int dir[][] = {{,},{,},{,-},{-,}};

struct node {
    int x, y, t, o;
    bool operator < (const node& p) const {
        return t > p.t;
    }
};
void bfs() {
    node t = (node) {
        sx, sy, ,
    };
    times[sx][sy][] = ;
    priority_queue<node> q;
    q.push(t);
    while(!q.empty()) {
        node u = q.top();
        q.pop();
        int x = u.x, y = u.y, o = u.o, t = u.t;

        if(x == ex && y == ey) {
            ans = min(ans, t);
            return;
        }
        for(int d = ; d < ; d++) {
            int tx = x + dir[d][];
            int ty = y + dir[d][];
            if(tx <  || tx >= n || ty <  || ty >= m) //越界
                continue;

            if(G[tx][ty] == '#') {
                if(o == ) {
                    continue;
                } else if(times[tx][ty][o-] > t + ) {

                    q.push((node) {
                        tx,ty,t+,o-
                    });

                    times[tx][ty][o-] = t + ;
                }
            } else if(G[tx][ty] == 'P' && times[tx][ty][o] > t) {

                q.push((node) {
                    tx,ty,t,o
                });

                times[tx][ty][o] = t;
            } else if(G[tx][ty] == 'B' && o <  && times[tx][ty][o + ] > t + ) {

                q.push((node) {
                    tx,ty,t+,o+
                });

                times[tx][ty][o + ] = t + ;
            } else if(times[tx][ty][o] > t + ) {

                q.push((node) {
                    tx,ty,t+,o
                });

                times[tx][ty][o] = t + ;
            }
        }
    }
}
int main() {

    while(~scanf("%d %d", &n, &m)) {
        if(n == )
            break;
        for(int i = ; i < maxN; i++)
            for(int j = ; j < maxN; j++)
                for(int k =  ; k <= ; k++)
                    times[i][j][k] = inf;
        for(int i = ; i < n; i++) {
            scanf("%s", G[i]);
        }
        for(int i = ; i < n; i++) {
            for(int j = ; j < m; j++) {
                if(G[i][j] == 'S')
                    sx = i, sy = j;
                if(G[i][j] == 'T')
                    ex = i, ey = j;
            }
        }

        ans = inf;
        bfs();
        if(ans == inf) {
            printf("-1\n");
        } else {
            printf("%d\n", ans);
        }
    }
    return ;
}