HDOJ 1180 诡异的楼梯

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//AC 中间处理有点不懂 
#include <iostream>
#include <cstdio>
#include <queue>
#include<cstring> 
using  namespace std;
 
struct Node {
    int x, y, step;
};
 
bool operator< ( Node n1, Node n2 ) {
    return n1.step > n2.step;
}
 
 
int n, m;
int dir[4][2] = { 0, 1, 1, 0, 0, -1, -1, 0 };
char mp[25][25];
bool mark[25][25];
Node _s;
void input() {
    int i, j;
    for( i=0; i<n; ++i ) scanf( "%s", mp[i] );
    for( i=0; i<n; ++i ) {
        for( j=0; j<n; ++j ) {
            if( mp[i][j] == 'S' ) {
                _s.x = i;
                _s.y = j;
                _s.step = 0;
            }
        }
    }
}
 
 
inline bool isBond( Node nd ) {
    if( nd.x < 0 || nd.y < 0 || nd.x >= n || nd.y >= m || mp[nd.x][nd.y] == '*' ) return 1;
    return 0;
}
 
 
int solve() {
    priority_queue<Node> Q;
    Node p, q;
    int i;
 
    Q.push( _s );
    memset(mark, 0, sizeof(mark));
    mark[_s.x][_s.y] = 1;
    while( !Q.empty() ) {
        p = Q.top();
        Q.pop();
        if( mp[p.x][p.y] == 'T' ) return p.step; //1.放这里判断比放for里面保险，虽然多花了点时间。
        for( i=0; i<4; ++i ) {
            q.x = p.x + dir[i][0];
            q.y = p.y + dir[i][1];
            q.step = p.step + 1;                 //2.走完后步数马上加
            if( isBond( q ) || mark[q.x][q.y] ) continue;
            if( mp[q.x][q.y] == '.' || mp[q.x][q.y] == 'T' ) {
                Q.push( q );
                mark[q.x][q.y] = 1;              //3.每次push后，马上跟新mark
                continue;
            } else if( mp[q.x][q.y] == '|' ) {
                if( p.step % 2 == 1 && i % 2 == 1 ) q.step ++;
                if( p.step % 2 == 0 && i % 2 == 0 ) q.step ++;
            } else if( mp[q.x][q.y] == '-' ) {
                if( p.step % 2 == 1 && i % 2 == 0 ) q.step ++;
                if( p.step % 2 == 0 && i % 2 == 1 ) q.step ++;
            }
            q.x += dir[i][0];
            q.y += dir[i][1];
            if( isBond(q) || mark[q.x][q.y] ) continue;
            Q.push( q );
            mark[q.x][q.y] = 1;
        }
    }
    return -1;
}
 
 
int main() {
//  freopen( "c:/aaa.txt", "r", stdin );
    while( scanf("%d %d", &n, &m) == 2 ) {
        input();
        printf( "%d\n", solve() );
    }
    return 0;
}