hdu 1728 BFS

#include <iostream>
#include <queue>
#include <cstdio>
#include <cstdlib>
using namespace std;

typedef struct{
int x, y;
int derect;
int num;
}Point;

int moves[][2] = { -1, 0, 0, 1, 1, 0, 0, -1 };
int mark[110][110];
int map[110][110];
int beginx, beginy, endx, endy, MAX;
int N, M;

void BFS(){
if( map[beginx][beginy] == 0 || map[endx][endy] == 0 ){
cout << "no" << endl;
return;
}

Point begin[4];
for( int i = 0; i < 4; i++ ){
begin[i].x = beginx + moves[i][0];
begin[i].y = beginy + moves[i][1];
begin[i].derect = i;
begin[i].num = 0;
}
mark[beginx][beginy] = 0;
queue<Point> q;
for( int i = 0; i < 4; i++ ){
if( begin[i].x >= 1 && begin[i].x <= M && begin[i].y >= 1 && begin[i].y <= N && map[begin[i].x][begin[i].y] ){
q.push( begin[i] );
mark[begin[i].x][begin[i].y] = begin[i].num;
}
}

while( !q.empty() ){
Point p;
p = q.front();
q.pop();
for( int i = 0; i < 4; i++ ){
Point temp;
temp.x = p.x + moves[i][0];
temp.y = p.y + moves[i][1];
temp.derect = i;
if( temp.derect != p.derect ){
temp.num = p.num + 1;
}else{
temp.num = p.num;
}
if( temp.x < 1 || temp.x > M || temp.y < 1 || temp.y > N || temp.num > MAX || map[temp.x][temp.y] == 0 ){
continue;
}
if( temp.x == endx && temp.y == endy ){
cout << "yes" << endl;
return;
}
if( temp.num <= mark[temp.x][temp.y] ){//注意这里有个等于号，因为虽然拐弯数相同，但方向可能不同！！！！
mark[temp.x][temp.y] = temp.num;
q.push( temp );
}
}
}
cout << "no" << endl;
}

int main(){
int t;
char c;
cin >> t;
while( t-- ){
cin >> M >> N;
getchar();
memset( map, 0, sizeof( map ) );
for( int i = 1; i <= M; i++ ){
for( int j = 1; j <= N; j++ ){
c = getchar();
if( c == '.'){
map[i][j] = 1;
}
mark[i][j] = 11;
}
getchar();
}
cin >> MAX >> beginy >> beginx >> endy >> endx;
BFS();
}
return 0;
}