失踪的博士

<p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">失踪的博士</span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p> <p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">话说<span>2007</span><span>年</span><span>8</span><span>月</span><span>5</span><span>日，</span><span>Mike</span><span>博士神秘失踪了，最后发现是被外星人绑架了，幸好外星人目前还是在地球上活动，并且知道外星人不了解地球，幸好，</span><span>Milk</span><span>博士身上有无线信号发送装置，我们终于确定了他的位置，必须赶快到那里去救他。</span></span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p> <p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">根据无线信号发送装置，我们确定出一张地图，为了尽快寻找到<span>Mike</span><span>博士，于是这个光荣和艰巨的任务便交给了你，编写程序，通过使用一张地图帮助研究所确定从研究所出发找到</span><span>Mike</span><span>博士最短距离。</span></span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p>

<p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">数据范围：&nbsp;<span>n&lt;=1000</span></span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p> <p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">输入格式</span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p> <p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">第一行为<span>n</span></span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p> <p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">第二行为<span>n*n</span><span>的地图（其中</span><span>0</span><span>表示通路，</span><span>1</span><span>表示死路）</span></span><span style="font-size:10.5000pt;font-family:'宋体';"></span> </p> <p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">最后两行每行有两个数字，分别表示研究所的坐标和博士信号所在的位置。</span> </p>

<p class="p0"> <span style="font-size:10.5000pt;font-family:'宋体';">一个数字<span>k</span><span>，表示从研究所出发找到</span><span>Milk</span><span>博士的最短距离。</span></span> </p>