{"id":116,"date":"2017-11-01T22:45:15","date_gmt":"2017-11-01T14:45:15","guid":{"rendered":"https:\/\/blog.indeex.club\/?p=116"},"modified":"2020-06-20T23:00:38","modified_gmt":"2020-06-20T15:00:38","slug":"%e5%9b%be%e5%bd%a2%e6%bc%94%e7%ae%97","status":"publish","type":"post","link":"https:\/\/blog.indeex.club\/index.php\/2017\/11\/01\/%e5%9b%be%e5%bd%a2%e6%bc%94%e7%ae%97\/","title":{"rendered":"\u56fe\u5f62\u6f14\u7b97"},"content":{"rendered":"<hr \/>\n<h4>\u7b80\u4ecb<\/h4>\n<p>\u5728\u79bb\u6563\u6570\u5b66\u3001\u7b97\u6cd5\u4e0e\u4eba\u667a\u80fd\u9886\u57df\uff0c\u5f88\u591a\u95ee\u9898\u53ef\u4ee5\u8868\u793a\u6210\u300c\u8282\u70b9\u4e0e\u8fde\u7ebf\u6240\u5f62\u6210\u7684\u56fe\u5f62\u300d\uff0c\u4e00\u4e2a\u7a0b\u5e8f\u8981\u89e3\u51b3\u67d0\u4e2a\u95ee\u9898\u5176\u5b9e\u662f\u5728\u8fd9\u4e2a\u56fe\u5f62\u91cc\u628a\u76ee\u6807\u8282\u70b9\u7ed9\u627e\u51fa\u6765\uff0c\u4e8e\u662f\u95ee\u9898\u6c42\u89e3\u5c31\u7b80\u5316\u6210\u4e86\u56fe\u5f62\u7684\u641c\u7d22\uff0c\u6211\u4eec\u53ea\u8981\u628a\u89e3\u7b54\u7ed9\u300c\u627e\u51fa\u6765\u300d\u5c31\u884c\u4e86\u3002<\/p>\n<p>\u56fe\u5f62\u641c\u7d22\u7684\u65b9\u6cd5\u5927\u81f4\u53ef\u4ee5\u5206\u4e3a\u300c\u6df1\u5ea6\u4f18\u5148\u641c\u5bfb(Depth-First Search, DFS)\u3001\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb(Breath-First Search, BFS)\u3001\u6700\u4f73\u4f18\u5148\u641c\u5bfb(Best-First Search, BestFS) \u4e09\u7c7b\u3002<\/p>\n<p>\u7136\u540e\u9488\u5bf9\u6700\u4f73\u4f18\u5148\u641c\u5bfb\u7684\u90e8\u4efd\uff0c\u8fd8\u6709\u4e00\u79cd\u5177\u6709\u7406\u8bba\u80cc\u666f\uff0c\u76f8\u5bf9\u5f3a\u5927\u597d\u7528\u7684A* \u7b97\u6cd5\u53ef\u7528\u3002<\/p>\n<h4>\u56fe\u5f62\u7684\u8868\u8fbe<\/h4>\n<p>\u56fe\u5f62\u662f\u7531\u8282\u70b9(node) \u4e0e\u8fde\u7ebf(edge) \u6240\u7ec4\u6210\u7684\u3002\u4e3e\u4f8b\u6765\u8bf4\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e2a\u5305\u542b\u516d\u4e2a\u8282\u70b9\u4e0e\u5341\u6761\u8fde\u7ebf\u7684\u7b80\u5355\u56fe\u5f62\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/graphSearch.jpg\" alt=\"\u56fe\u5f62\u6f14\u7b97\" \/><br \/>\n<\/center><\/p>\n<h4>\u6df1\u5ea6\u4f18\u5148\u641c\u5bfb<\/h4>\n<p>\u6240\u8c13\u7684\u300c\u6df1\u5ea6\u4f18\u5148\u641c\u5bfb\u300d (Depth-First Search, DFS)\uff0c\u5c31\u662f\u4e00\u76f4\u5f80\u5c1a\u672a\u8bbf\u95ee\u8fc7\u7684\u7b2c\u4e00\u4e2a\u90bb\u5c45\u8282\u70b9\u8d70\u53bb\u7684\u4e00\u79cd\u65b9\u6cd5\uff0c\u8fd9\u79cd\u65b9\u6cd5\u53ef\u4ee5\u91c7\u7528\u7a0b\u5f0f\u8bbe\u8ba1\u4e2d\u7684\u300c\u9012\u5f52\u300d\u5b8c\u6210\uff0c\u4ee5\u4e0b\u662f\u6df1\u5ea6\u641c\u5bfb\u7684\u6f14\u7b97\u6cd5\uff1a<\/p>\n<pre><code class=\"language-javascript line-numbers\">function dfs(g, node) {\n  if (g[node].v !=0) return;   \/\/ \u5982\u679c\u5df2\u8bbf\u95ee\u8fc7\uff0c\u5c31\u4e0d\u518d\u8bbf\u95ee\n  printf(\"%d=&gt;\", node);       \/\/ \u5426\u5219\uff0c\u6253\u5370\u8282\u70b9\n  g[node].v = 1;              \/\/   \u5e76\u8bbe\u5b9a\u4e3a\u5df2\u8bbf\u95ee\n  var neighbors = g[node].n;  \/\/ \u53d6\u51fa\u76f8\u90bb\u8282\u70b9\n  for (var i in neighbors) {  \/\/ \u5bf9\u4e8e\u6bcf\u4e2a\u76f8\u90bb\u8282\u70b9\u9010\u4e00\u8bbf\u95ee\n  }\n}\n<\/code><\/pre>\n<p>\u9488\u5bf9\u4e0a\u8ff0\u7684\u56fe\u5f62\uff0c\u82e5\u91c7\u7528\u6df1\u5ea6\u4f18\u5148\u641c\u5bfb\uff0c\u5176\u7ed3\u679c\u53ef\u80fd\u5982\u4e0b\u6240\u793a(\u56fe\u4e2d\u7ea2\u8272\u7684\u6570\u5b57\u4ee3\u8868\u8bbf\u95ee\u987a\u5e8f)<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/dfs.jpg\" alt=\"\u56fe\u5f62\u6f14\u7b97\" \/><br \/>\n<\/center><\/p>\n<h4>\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb<\/h4>\n<p>\u867d\u7136\u6df1\u5ea6\u4f18\u5148\u641c\u5bfb\u53ef\u4ee5\u641c\u5bfb\u6574\u4e2a\u56fe\u5f62\uff0c\u4f46\u662f\u5374\u5f88\u53ef\u80fd\u7ed5\u4e86\u5f88\u4e45\u624d\u627e\u5230\u76ee\u6807\uff0c\u4e8e\u662f\u4ece\u8d77\u70b9\u5230\u76ee\u6807\u53ef\u80fd\u4f1a\u82b1\u8d39\u5f88\u4e45\u7684\u65f6\u95f4(\u6216\u8bf4\u8def\u5f84\u957f\u5ea6\u8fc7\u957f)\u3002<\/p>\n<p>\u5982\u679c\u6211\u4eec\u60f3\u627e\u51fa\u5230\u8fbe\u76ee\u6807\u6700\u5c11\u7684\u6b65\u9aa4\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u91c7\u7528\u300c\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb\u300d (Breath-First Search, BFS) \u7684\u65b9\u5f0f\u3002<\/p>\n<p>\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfbBFS \u662f\u4ece\u4e00\u4e2a\u8282\u70b9\u5f00\u59cb\uff0c\u5c06\u6bcf\u4e2a\u90bb\u5c45\u8282\u70b9\u90fd\u4e00\u5c42\u4e00\u5c42\u7684\u62dc\u8bbf\u4e0b\u53bb\uff0c\u6df1\u5ea6\u6700\u6d45\u7684\u8282\u70b9\u4f1a\u4f18\u5148\u88ab\u62dc\u8bbf\u7684\u65b9\u5f0f\u3002<\/p>\n<p>\u4e3e\u4f8b\u800c\u8a00\uff0c\u9488\u5bf9\u4e0a\u8ff0\u7684\u56fe\u5f62\u793a\u4f8b\uff0c\u82e5\u91c7\u7528\u300c\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfbBFS \u300d\u7684\u65b9\u5f0f\uff0c\u90a3\u4e48\u62dc\u8bbf\u987a\u5e8f\u5c06\u4f1a\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/bfs.jpg\" alt=\"\u56fe\u5f62\u6f14\u7b97\" \/><br \/>\n<\/center><\/p>\n<p>\u8981\u80fd\u7528\u7a0b\u5f0f\u8fdb\u884c\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb\uff0c\u5fc5\u987b\u91c7\u7528\u300c\u5148\u8fdb\u5148\u51fa\u300d(First-in First-Out, FIFO) \u7684\u65b9\u5f0f\u7ba1\u7406\u8282\u70b9\uff0c\u56e0\u6b64\u901a\u5e38\u5728\u300c\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb\u300d\u91cc\u4f1a\u6709\u4e2a\u4f2b\u5217(queue) \u7ed3\u6784\uff0c\u4ee5\u4e0b\u662fBFS \u7684\u6f14\u7b97\u6cd5\u7247\u6bb5\uff1a<\/p>\n<pre><code class=\"language-javascript line-numbers\">function bfs(g, q) { \/\/ \u5e7f\u5ea6\u4f18\u5148\u641c\u7d22\n  if (q.length == 0) return; \/\/ \u5982\u679c queue \u5df2\u7a7a\uff0c\u5219\u8fd4\u56de\u3002\n  var node = dequeue(q);     \/\/ \u5426\u5219\u3001\u53d6\u51fa queue \u7684\u7b2c\u4e00\u4e2a\u8282\u70b9\u3002\n  if (g[node].v == 0)        \/\/ \u5982\u679c\u8be5\u8282\u70b9\u5c1a\u672a\u62dc\u8bbf\u8fc7\u3002\n    g[node].v = 1;           \/\/   \u6807\u8bb0\u4e3a\u5df2\u62dc\u8bbf\n  else                       \/\/ \u5426\u5219 (\u5df2\u62dc\u8bbf\u8fc7)\n    return;                  \/\/   \u4e0d\u7ee7\u7eed\u641c\u5bfb\uff0c\u76f4\u63a5\u8fd4\u56de\u3002\n  printf(\"%d=&gt;\", node);      \/\/ \u5370\u51fa\u8282\u70b9\n  var neighbors = g[node].n; \/\/ \u53d6\u51fa\u90bb\u5c45\u3002\n  for (var i in neighbors) { \/\/ \u5bf9\u4e8e\u6bcf\u4e2a\u90bb\u5c45\n    var n = neighbors[i];\n    if (!g[n].visited)       \/\/ \u5047\u5982\u8be5\u90bb\u5c45\u8fd8\u6ca1\u6709\u88ab\u62dc\u8bbf\u8fc7\n      q.push(n);             \/\/   \u5c31\u653e\u5165 queue \u4e2d\n  }\n  bfs(g, q);\n}\n<\/code><\/pre>\n<h4>\u6700\u4f73\u4f18\u5148\u641c\u5bfb<\/h4>\n<p>\u4f46\u662f\u3001\u4e0a\u8ff0\u4e24\u4e2a\u65b9\u6cd5\u5176\u5b9e\u90fd\u8fd8\u4e0d\u591f\u597d\uff0c\u6df1\u5ea6\u641c\u5bfb\u4f1a\u6d2a\u6c34\u731b\u517d\u4e00\u6837\u4e71\u51b2\u4e71\u649e\uff0c\u800c\u5e7f\u5ea6\u641c\u5bfb\u5219\u4f1a\u8017\u8d39\u592a\u591a\u7684\u8d44\u6e90\uff0c\u5e76\u4e14\u6ca1\u6709\u6548\u7387\uff0c\u65e0\u6cd5\u5f88\u5feb\u7684\u627e\u5230\u76ee\u6807\u70b9\u3002<\/p>\n<p>\u5047\u5982\u6211\u4eec\u80fd\u591f\u77e5\u9053\u54ea\u4e9b\u70b9\u8ddd\u79bb\u76ee\u6807\u70b9\u6700\u8fd1\uff0c\u4e5f\u5c31\u662f\u54ea\u4e9b\u70b9\u6bd4\u8f83\u597d\u7684\u8bdd\uff0c\u90a3\u5c31\u80fd\u91c7\u7528\u300c\u6700\u4f73\u4f18\u5148\u641c\u5bfb(Best-First Search) \u7684\u65b9\u5f0f\u6765\u641c\u5bfb\u4e86\u3002<\/p>\n<p>\u6700\u4f73\u4f18\u5148\u641c\u5bfb\u7684\u5b9e\u4f5c\u65b9\u6cd5\u4e0e\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb\u7c7b\u4f3c\uff0c\u4f46\u662f\u5e76\u4e0d\u91c7\u7528\u4f2b\u5217(queue) \uff0c\u800c\u662f\u91c7\u7528\u4e00\u79cd\u6839\u636e\u4f18\u5148\u7a0b\u5ea6\u6392\u5e8f\u7684\u7ed3\u6784\uff0c\u6bcf\u6b21\u90fd\u53d6\u51fa\u6700\u597d\u7684\u90a3\u4e2a\u7ee7\u7eed\u8fdb\u884c\u641c\u5bfb\u3002<\/p>\n<p>\u4f46\u662f\u3001\u8282\u70b9\u7684\u597d\u574f\u901a\u5e38\u5f88\u96be\u8bc4\u4f30\uff0c\u5355\u7eaf\u91c7\u7528\u67d0\u79cd\u8ddd\u79bb\u53bb\u8bc4\u4f30\u5f80\u5f80\u4f1a\u8fc7\u5ea6\u7b80\u5316\u95ee\u9898\uff0c\u8fd9\u70b9\u5f80\u5f80\u662f\u6700\u4f73\u4f18\u5148\u641c\u5bfb\u7684\u56f0\u96be\u4e4b\u6240\u5728\u3002<\/p>\n<p>\u8fd8\u597d\uff0c\u6709\u65f6\u6211\u4eec\u4e0d\u9700\u8981\u975e\u5e38\u7cbe\u786e\u7684\u8bc4\u4f30\uff0c\u53ea\u8981\u95ee\u9898\u7b26\u5408$h(x) \\leq d(x,y) + h(y) $\u8fd9\u6837\u7684\u5355\u8c03(monotone)\u7279\u6027\uff0c\u5c31\u53ef\u4ee5\u4f7f\u7528A<em>\u7b97\u6cd5\u6765\u8fdb\u884c\u8f83\u5feb\u901f\u7684\u641c\u5bfb\uff0c\u8fd9\u79cd\u65b9\u6cd5\u6bd4\u5e7f\u5ea6\u4f18\u5148\u641c\u5bfb\u901a\u5e38\u5feb\u5f88\u591a\uff0c\u56e0\u4e3aA<\/em>\u4e0d\u4f1a\u641c\u5bfb\u6240\u6709\u8282\u70b9\uff0c\u800c\u662f\u6709\u7cfb\u7edf\u7684\u671d\u7740\u6574\u4f53\u8f83\u597d\u7684\u65b9\u5411\u524d\u8fdb\uff0c\u8fd9\u79cd\u65b9\u6cd5\u5728\u7535\u8111\u6e38\u620f(Game)\u4e0a\u5e38\u88ab\u7528\u5728NPC (\u975e\u4eba\u7c7b\u89d2\u8272)\u7684\u667a\u6167\u578b\u641c\u5bfb\u884c\u4e3a\u8bbe\u8ba1\u4e0a\u9762\uff0c\u662f\u4eba\u5de5\u667a\u6167\u641c\u5bfb\u65b9\u6cd5\u4e2d\u8f83\u5f3a\u5927\u7684\u4e00\u79cd\u3002<\/p>\n<p>code enjoy!   \u0669(\u0e51\u275b\u1d17\u275b\u0e51)\u06f6<\/p>\n<p>\u4f5c\u8005\uff1aindeex<\/p>\n<p>\u94fe\u63a5\uff1a<a class=\"wp-editor-md-post-content-link\" href=\"http:\/\/indeex.cc\/\">http:\/\/indeex.cc<\/a><\/p>\n<p>\u8457\u4f5c\u6743\u5f52\u4f5c\u8005\u6240\u6709\u3002\u5546\u4e1a\u8f6c\u8f7d\u8bf7\u8054\u7cfb\u4f5c\u8005\u83b7\u5f97\u6388\u6743\uff0c\u975e\u5546\u4e1a\u8f6c\u8f7d\u8bf7\u6ce8\u660e\u51fa\u5904\u3002<\/p>\n<hr \/>\n","protected":false},"excerpt":{"rendered":"<p>\u7b80\u4ecb \u5728\u79bb\u6563\u6570\u5b66\u3001\u7b97\u6cd5\u4e0e\u4eba\u667a\u80fd\u9886\u57df\uff0c\u5f88\u591a\u95ee\u9898\u53ef\u4ee5\u8868\u793a\u6210\u300c\u8282\u70b9\u4e0e\u8fde\u7ebf\u6240\u5f62\u6210\u7684\u56fe\u5f62\u300d\uff0c\u4e00\u4e2a\u7a0b\u5e8f\u8981\u89e3\u51b3\u67d0\u4e2a<a href=\"https:\/\/blog.indeex.club\/index.php\/2017\/11\/01\/%e5%9b%be%e5%bd%a2%e6%bc%94%e7%ae%97\/\" class=\"read-more\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[4],"_links":{"self":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/116"}],"collection":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/comments?post=116"}],"version-history":[{"count":1,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/116\/revisions"}],"predecessor-version":[{"id":119,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/116\/revisions\/119"}],"wp:attachment":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/media?parent=116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/categories?post=116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/tags?post=116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}