\u8fd9\u9898\u672c\u8d28\u4e0a\u662f\u4e00\u4e2a\u62d3\u6251\u6392\u5e8ftopological sort\uff0c\u9700\u8981\u5224\u65ad\u6709\u6ca1\u6709\u73af\u6765\u5904\u7406\u65e0\u6548input\uff0c\u96be\u5ea6\u4e3b\u8981\u6765\u81ea\u8fd9\u90e8\u5206\u3002Topological sort\u53ef\u4ee5\u7528dfs\u89e3\u51b3\uff0c\u4f46\u662f\u6ca1\u7ec3\u4e60\u8fc7\u8fd8\u4e0d\u4e0d\u5bb9\u6613\u5199\u5bf9\u7684\u3002\u5148\u4e0a\u4e00\u4e2a\u6211\u6bd4\u8f83\u6ee1\u610f\u7684python\u89e3\u6cd5\u3002<\/p>\n\n\n\n
class Solution:\n def alienOrder(self, words: List[str]) -> str:\n edges = {c: [] for word in words for c in word}\n for word1, word2 in zip(words, words[1:]):\n if len(word1) > len(word2) and word1.startswith(word2):\n return ''\n for c1, c2 in zip(word1, word2):\n if c1 != c2:\n edges[c1].append(c2)\n break\n \n seen = {}\n order = []\n def dfs(start):\n if start in seen:\n return seen[start]\n seen[start] = False\n for nxt in edges[start]:\n if not dfs(nxt):\n return False\n order.insert(0, start)\n seen[start] = True\n return True\n \n if not all(dfs(start) for start in edges):\n return ''\n return ''.join(order)<\/code><\/pre>\n\n\n\n\u603b\u7ed3\u4e00\u4e0b\u8981\u70b9\u3002
1. edges = {c: [] for word in words for c in word} \u8fd9\u79cd\u4e00\u884c\u4e24\u4e2a\u5faa\u73af\u5efamap\u7684\u65b9\u5f0f\u6211\u4e5f\u662f\u65b0\u5b66\u7684\uff0c\u5f88\u65b9\u4fbf\u3002\u8fd9\u4e2amap key\u662f\u6392\u524d\u9762\u7684\u5b57\u6bcd\uff0cvalue\u662f\u6392\u540e\u9762\u7684\u5b57\u6bcd\u3002\u800c\u4e14\u4e0d\u7ba1\u6709\u6ca1\u6709\u540e\u9762\u7684\uff0ckey\u90fd\u52a0\u4e0a\u4e86\uff0c\u8fd9\u6837\u7701\u4e86\u53e6\u4e00\u4e2a\u53d8\u91cf\u5b58\u5b57\u6bcd\u8868\uff0c\u53ef\u4ee5\u5bf9\u6bd4\u6211\u4e4b\u524d\u4e00\u4e2a\u5199\u5bf9\u4e0d\u90a3\u4e48\u597d\u7684\u89e3\u6cd5\u3002
2. \u7528zip\u904d\u5386pair\u5f88\u597d\u7528\uff0c\u51cf\u5c11\u4e86\u51faindex bug\u7684\u53ef\u80fd
3. len(word1) > len(word2) and word1.startswith(word2)\uff0c\u8fd9\u662f\u4e00\u4e2a\u7279\u6b8a\u7684case\u3002\u6bd4\u5982abc\u6392\u5728ab\u524d\u9762\uff0c\u4e0d\u7ba1\u4ec0\u4e48\u5b57\u6bcd\u8868\u987a\u5e8f\uff0c\u5c31\u662fc\u6392\u5728\u7a7a\u524d\u9762\uff0c\u90a3\u662f\u65e0\u6548\u7684\u3002
4. seen\u7684\u5229\u7528\uff0c\u8fd9\u662f\u6700\u5de7\u5999\u7684\u5730\u65b9\u3002\u5199\u4e86\u51e0\u79cd\u5c1d\u8bd5\uff0c\u53d1\u73b0\u73af\u4e0d\u592a\u5bb9\u6613\u3002\u5982\u679c\u53ea\u7528\u4e00\u4e2aset\u8bb0\u5f55visited\uff0c\u5c31\u65e0\u6cd5\u533a\u5206\u662f\u4e00\u6761\u5df2\u7ecf\u8d70\u901a\u7684\u8def\u8fd8\u662f\u5f53\u524d\u8fd9\u6761\u8def\u53c8\u56de\u5230\u67d0\u4e2a\u4e4b\u524d\u7ecf\u8fc7\u7684\u4e00\u70b9\u3002\u89e3\u6cd5\u65b9\u6cd5\u53ef\u4ee5\u7528\u4e00\u4e2aset\u8bb0\u5f55visited\uff0c\u53ea\u52a0\u4e0d\u51cf\uff0c\u53e6\u4e00\u4e2aset\u8bb0\u5f55\u5f53\u524d\u8fd9\u6761\u8def\u7684\u8def\u5f84\uff0c\u56de\u6eaf\u65f6\u8981\u66f4\u65b0\uff0c\u6bd4\u8f83\u9ebb\u70e6\u3002\u8fd9\u79cd\u89e3\u6cd5\u5229\u7528\u4e86False\u548cTrue\u4e24\u79cdstates\uff0cFalse\u4ee3\u8868\u6b63\u5728\u8d70\u7684\u8def\uff0cTrue\u4ee3\u8868\u4ee5\u524d\u5df2\u7ecf\u8d70\u5230\u5e95\u80fd\u8d70\u901a\u7684\u8def\u3002\u975e\u5e38\u6df1\u523b\uff0c\u6211\u60f3\u4e86\u5f88\u4e45\u624d\u7b97\u5927\u6982\u7406\u89e3\u3002
5. if not all(dfs(start) for start in edges)\uff0call\u662f\u4e2a\u6211\u65b0\u5b66\u7684function\uff0cinput\u662fcollection\u6216\u8005\u66f4\u51c6\u786e\u8bf4\u662f\u53ef\u4ee5iterable\u7684\u4e1c\u897f\uff0c\u5c31\u662f\u8981\u6bcf\u4e2a\u5143\u7d20\u90fd\u662ftrue\u5c31\u662ftrue\u3002\u6362\u53e5\u8bdd\u8bf4\u5c31\u50cf\u5f00\u5173\u4e32\u8054\u3002\u672c\u6765\u6211\u5199\u5f97\u662fall([dfs(start) for start in edges])\uff0c\u540e\u6765\u53d1\u73b0\u4ee3\u8868list\u7684\u65b9\u62ec\u53f7\u53ef\u4ee5\u7701\u7565\uff0c\u4f30\u8ba1\u662f\u4e9b\u8bed\u6cd5\u7cd6\u3002Python\u91cc\u9762\u786e\u5b9e\u6709\u5f88\u591a\u6211\u4e0d\u77e5\u9053\u7684\u8bed\u6cd5\u7cd6\u3002
6. dfs\u662f\u51fd\u6570\u5185\u5b9a\u4e49\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u7701\u4e86self\u548c\u7528\u5185\u51fd\u6570\u5916\u7684\u53d8\u91cf\u4fdd\u5b58\u72b6\u6001\uff0c\u4e0d\u7528\u6bcf\u4e2arecursion call\u90fdpass\u4e00\u6b21\u3002<\/p>\n\n\n\n
\u505a\u5b8c\u8fd9\u9898\u540e\uff0c\u91cd\u65b0\u505acourse schedule<\/a>\u5c31\u5bb9\u6613\u591a\u4e86\u3002<\/p>\n\n\n\n\u4e0b\u9762\u662f\u4e00\u4e2a\u6211\u4e4b\u524d\u5199\u5f97\u6bd4\u8f83\u957f\uff0c\u5f88\u5bb9\u6613\u51fabug\u7684\u7248\u672c\uff0c\u53ef\u4ee5\u5bf9\u6bd4\u4e00\u4e0b\u3002<\/p>\n\n\n\n
class Solution(object):\n def alienOrder(self, words):\n \"\"\"\n :type words: List[str]\n :rtype: str\n \"\"\"\n if len(words) == 0:\n return ''\n if len(words) == 1:\n return ''.join(set([c for c in words]))\n edges = {}\n voca = set()\n for i in xrange(len(words) - 1):\n for j in xrange(i + 1, len(words)):\n if len(words[i]) > len(words[j]) and words[i].startswith(words[j]):\n return ''\n self.addEdge(words[i], words[j], edges, voca)\n \n visited = set()\n order = []\n for c in voca:\n # c = voca.pop()\n this_visit = set()\n noloop = self.dfs(c, edges, visited, this_visit, order)\n if not noloop:\n return ''\n return ''.join(order)\n \n def dfs(self, start, edges, visited, this_visited, order):\n if start in this_visited:\n return False\n\n if start in visited:\n return True\n\n visited.add(start)\n this_visited.add(start)\n\n if start not in edges:\n order.insert(0, start)\n this_visited.remove(start)\n return True\n\n for nxt in edges[start]:\n noloop = self.dfs(nxt, edges, visited, this_visited, order)\n if not noloop:\n return False\n order.insert(0, start)\n this_visited.remove(start)\n return True\n\n def addEdge(self, word1, word2, edges, voca):\n voca.update([c for c in word1])\n voca.update([c for c in word2])\n for i in xrange(min(len(word1), len(word2))):\n if word1[i] != word2[i]:\n if word1[i] in edges:\n edges[word1[i]].add(word2[i])\n else:\n edges[word1[i]] = set([word2[i]])\n break<\/code><\/pre>\n\n\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
\u8fd9\u9898\u672c\u8d28\u4e0a\u662f\u4e00\u4e2a\u62d3\u6251\u6392\u5e8ftopological sort\uff0c\u9700\u8981\u5224\u65ad\u6709\u6ca1\u6709\u73af\u6765\u5904\u7406\u65e0\u6548input\uff0c\u96be\u5ea6\u4e3b\u8981\u6765\u81ea\u8fd9\u90e8\u5206\u3002Topological sort\u53ef\u4ee5\u7528dfs\u89e3\u51b3\uff0c\u4f46\u662f\u6ca1\u7ec3\u4e60\u8fc7\u8fd8\u4e0d\u4e0d\u5bb9\u6613\u5199\u5bf9\u7684\u3002\u5148\u4e0a\u4e00\u4e2a\u6211\u6bd4\u8f83\u6ee1\u610f\u7684python\u89e3\u6cd5\u3002 \u603b\u7ed3\u4e00\u4e0b\u8981\u70b9\u30021. edges = {c: [] for word in words for c in word} \u8fd9\u79cd\u4e00\u884c\u4e24\u4e2a\u5faa\u73af\u5efamap\u7684\u65b9\u5f0f\u6211\u4e5f\u662f\u65b0\u5b66\u7684\uff0c\u5f88\u65b9\u4fbf\u3002\u8fd9\u4e2amap key\u662f\u6392\u524d\u9762\u7684\u5b57\u6bcd\uff0cvalue\u662f\u6392\u540e\u9762\u7684\u5b57\u6bcd\u3002\u800c\u4e14\u4e0d\u7ba1\u6709\u6ca1\u6709\u540e\u9762\u7684\uff0ckey\u90fd\u52a0\u4e0a\u4e86\uff0c\u8fd9\u6837\u7701\u4e86\u53e6\u4e00\u4e2a\u53d8\u91cf\u5b58\u5b57\u6bcd\u8868\uff0c\u53ef\u4ee5\u5bf9\u6bd4\u6211\u4e4b\u524d\u4e00\u4e2a\u5199\u5bf9\u4e0d\u90a3\u4e48\u597d\u7684\u89e3\u6cd5\u30022. \u7528zip\u904d\u5386pair\u5f88\u597d\u7528\uff0c\u51cf\u5c11\u4e86\u51faindex bug\u7684\u53ef\u80fd3. len(word1) > len(word2) and word1.startswith(word2)\uff0c\u8fd9\u662f\u4e00\u4e2a\u7279\u6b8a\u7684case\u3002\u6bd4\u5982abc\u6392\u5728ab\u524d\u9762\uff0c\u4e0d\u7ba1\u4ec0\u4e48\u5b57\u6bcd\u8868\u987a\u5e8f\uff0c\u5c31\u662fc\u6392\u5728\u7a7a\u524d\u9762\uff0c\u90a3\u662f\u65e0\u6548\u7684\u30024. seen\u7684\u5229\u7528\uff0c\u8fd9\u662f\u6700\u5de7\u5999\u7684\u5730\u65b9\u3002\u5199\u4e86\u51e0\u79cd\u5c1d\u8bd5\uff0c\u53d1\u73b0\u73af\u4e0d\u592a\u5bb9\u6613\u3002\u5982\u679c\u53ea\u7528\u4e00\u4e2aset\u8bb0\u5f55visited\uff0c\u5c31\u65e0\u6cd5\u533a\u5206\u662f\u4e00\u6761\u5df2\u7ecf\u8d70\u901a\u7684\u8def\u8fd8\u662f\u5f53\u524d\u8fd9\u6761\u8def\u53c8\u56de\u5230\u67d0\u4e2a\u4e4b\u524d\u7ecf\u8fc7\u7684\u4e00\u70b9\u3002\u89e3\u6cd5\u65b9\u6cd5\u53ef\u4ee5\u7528\u4e00\u4e2aset\u8bb0\u5f55visited\uff0c\u53ea\u52a0\u4e0d\u51cf\uff0c\u53e6\u4e00\u4e2aset\u8bb0\u5f55\u5f53\u524d\u8fd9\u6761\u8def\u7684\u8def\u5f84\uff0c\u56de\u6eaf\u65f6\u8981\u66f4\u65b0\uff0c\u6bd4\u8f83\u9ebb\u70e6\u3002\u8fd9\u79cd\u89e3\u6cd5\u5229\u7528\u4e86False\u548cTrue\u4e24\u79cdstates\uff0cFalse\u4ee3\u8868\u6b63\u5728\u8d70\u7684\u8def\uff0cTrue\u4ee3\u8868\u4ee5\u524d\u5df2\u7ecf\u8d70\u5230\u5e95\u80fd\u8d70\u901a\u7684\u8def\u3002\u975e\u5e38\u6df1\u523b\uff0c\u6211\u60f3\u4e86\u5f88\u4e45\u624d\u7b97\u5927\u6982\u7406\u89e3\u30025. if not all(dfs(start) for start in edges)\uff0call\u662f\u4e2a\u6211\u65b0\u5b66\u7684function\uff0cinput\u662fcollection\u6216\u8005\u66f4\u51c6\u786e\u8bf4\u662f\u53ef\u4ee5iterable\u7684\u4e1c\u897f\uff0c\u5c31\u662f\u8981\u6bcf\u4e2a\u5143\u7d20\u90fd\u662ftrue\u5c31\u662ftrue\u3002\u6362\u53e5\u8bdd\u8bf4\u5c31\u50cf\u5f00\u5173\u4e32\u8054\u3002\u672c\u6765\u6211\u5199\u5f97\u662fall([dfs(start) for start in edges])\uff0c\u540e\u6765\u53d1\u73b0\u4ee3\u8868list\u7684\u65b9\u62ec\u53f7\u53ef\u4ee5\u7701\u7565\uff0c\u4f30\u8ba1\u662f\u4e9b\u8bed\u6cd5\u7cd6\u3002Python\u91cc\u9762\u786e\u5b9e\u6709\u5f88\u591a\u6211\u4e0d\u77e5\u9053\u7684\u8bed\u6cd5\u7cd6\u30026. dfs\u662f\u51fd\u6570\u5185\u5b9a\u4e49\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u7701\u4e86self\u548c\u7528\u5185\u51fd\u6570\u5916\u7684\u53d8\u91cf\u4fdd\u5b58\u72b6\u6001\uff0c\u4e0d\u7528\u6bcf\u4e2arecursion call\u90fdpass\u4e00\u6b21\u3002 \u505a\u5b8c\u8fd9\u9898\u540e\uff0c\u91cd\u65b0\u505acourse…
Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false},"categories":[1],"tags":[],"yoast_head":"\n\u7b97\u6cd5\u7ec3\u4e60 Leetcode \u529b\u6263 269. Alien Dictionary \u89e3\u6cd5 | Feel Like Learning<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/feellikelearning.com\/index.php\/2020\/06\/20\/leetcode-269-alien-dictionary-solution\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u7b97\u6cd5\u7ec3\u4e60 Leetcode \u529b\u6263 269. Alien Dictionary \u89e3\u6cd5 | Feel Like Learning\" \/>\n<meta property=\"og:description\" content=\"\u8fd9\u9898\u672c\u8d28\u4e0a\u662f\u4e00\u4e2a\u62d3\u6251\u6392\u5e8ftopological sort\uff0c\u9700\u8981\u5224\u65ad\u6709\u6ca1\u6709\u73af\u6765\u5904\u7406\u65e0\u6548input\uff0c\u96be\u5ea6\u4e3b\u8981\u6765\u81ea\u8fd9\u90e8\u5206\u3002Topological sort\u53ef\u4ee5\u7528dfs\u89e3\u51b3\uff0c\u4f46\u662f\u6ca1\u7ec3\u4e60\u8fc7\u8fd8\u4e0d\u4e0d\u5bb9\u6613\u5199\u5bf9\u7684\u3002\u5148\u4e0a\u4e00\u4e2a\u6211\u6bd4\u8f83\u6ee1\u610f\u7684python\u89e3\u6cd5\u3002 \u603b\u7ed3\u4e00\u4e0b\u8981\u70b9\u30021. edges = {c: [] for word in words for c in word} \u8fd9\u79cd\u4e00\u884c\u4e24\u4e2a\u5faa\u73af\u5efamap\u7684\u65b9\u5f0f\u6211\u4e5f\u662f\u65b0\u5b66\u7684\uff0c\u5f88\u65b9\u4fbf\u3002\u8fd9\u4e2amap key\u662f\u6392\u524d\u9762\u7684\u5b57\u6bcd\uff0cvalue\u662f\u6392\u540e\u9762\u7684\u5b57\u6bcd\u3002\u800c\u4e14\u4e0d\u7ba1\u6709\u6ca1\u6709\u540e\u9762\u7684\uff0ckey\u90fd\u52a0\u4e0a\u4e86\uff0c\u8fd9\u6837\u7701\u4e86\u53e6\u4e00\u4e2a\u53d8\u91cf\u5b58\u5b57\u6bcd\u8868\uff0c\u53ef\u4ee5\u5bf9\u6bd4\u6211\u4e4b\u524d\u4e00\u4e2a\u5199\u5bf9\u4e0d\u90a3\u4e48\u597d\u7684\u89e3\u6cd5\u30022. \u7528zip\u904d\u5386pair\u5f88\u597d\u7528\uff0c\u51cf\u5c11\u4e86\u51faindex bug\u7684\u53ef\u80fd3. len(word1) > len(word2) and word1.startswith(word2)\uff0c\u8fd9\u662f\u4e00\u4e2a\u7279\u6b8a\u7684case\u3002\u6bd4\u5982abc\u6392\u5728ab\u524d\u9762\uff0c\u4e0d\u7ba1\u4ec0\u4e48\u5b57\u6bcd\u8868\u987a\u5e8f\uff0c\u5c31\u662fc\u6392\u5728\u7a7a\u524d\u9762\uff0c\u90a3\u662f\u65e0\u6548\u7684\u30024. seen\u7684\u5229\u7528\uff0c\u8fd9\u662f\u6700\u5de7\u5999\u7684\u5730\u65b9\u3002\u5199\u4e86\u51e0\u79cd\u5c1d\u8bd5\uff0c\u53d1\u73b0\u73af\u4e0d\u592a\u5bb9\u6613\u3002\u5982\u679c\u53ea\u7528\u4e00\u4e2aset\u8bb0\u5f55visited\uff0c\u5c31\u65e0\u6cd5\u533a\u5206\u662f\u4e00\u6761\u5df2\u7ecf\u8d70\u901a\u7684\u8def\u8fd8\u662f\u5f53\u524d\u8fd9\u6761\u8def\u53c8\u56de\u5230\u67d0\u4e2a\u4e4b\u524d\u7ecf\u8fc7\u7684\u4e00\u70b9\u3002\u89e3\u6cd5\u65b9\u6cd5\u53ef\u4ee5\u7528\u4e00\u4e2aset\u8bb0\u5f55visited\uff0c\u53ea\u52a0\u4e0d\u51cf\uff0c\u53e6\u4e00\u4e2aset\u8bb0\u5f55\u5f53\u524d\u8fd9\u6761\u8def\u7684\u8def\u5f84\uff0c\u56de\u6eaf\u65f6\u8981\u66f4\u65b0\uff0c\u6bd4\u8f83\u9ebb\u70e6\u3002\u8fd9\u79cd\u89e3\u6cd5\u5229\u7528\u4e86False\u548cTrue\u4e24\u79cdstates\uff0cFalse\u4ee3\u8868\u6b63\u5728\u8d70\u7684\u8def\uff0cTrue\u4ee3\u8868\u4ee5\u524d\u5df2\u7ecf\u8d70\u5230\u5e95\u80fd\u8d70\u901a\u7684\u8def\u3002\u975e\u5e38\u6df1\u523b\uff0c\u6211\u60f3\u4e86\u5f88\u4e45\u624d\u7b97\u5927\u6982\u7406\u89e3\u30025. if not all(dfs(start) for start in edges)\uff0call\u662f\u4e2a\u6211\u65b0\u5b66\u7684function\uff0cinput\u662fcollection\u6216\u8005\u66f4\u51c6\u786e\u8bf4\u662f\u53ef\u4ee5iterable\u7684\u4e1c\u897f\uff0c\u5c31\u662f\u8981\u6bcf\u4e2a\u5143\u7d20\u90fd\u662ftrue\u5c31\u662ftrue\u3002\u6362\u53e5\u8bdd\u8bf4\u5c31\u50cf\u5f00\u5173\u4e32\u8054\u3002\u672c\u6765\u6211\u5199\u5f97\u662fall([dfs(start) for start in edges])\uff0c\u540e\u6765\u53d1\u73b0\u4ee3\u8868list\u7684\u65b9\u62ec\u53f7\u53ef\u4ee5\u7701\u7565\uff0c\u4f30\u8ba1\u662f\u4e9b\u8bed\u6cd5\u7cd6\u3002Python\u91cc\u9762\u786e\u5b9e\u6709\u5f88\u591a\u6211\u4e0d\u77e5\u9053\u7684\u8bed\u6cd5\u7cd6\u30026. dfs\u662f\u51fd\u6570\u5185\u5b9a\u4e49\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u7701\u4e86self\u548c\u7528\u5185\u51fd\u6570\u5916\u7684\u53d8\u91cf\u4fdd\u5b58\u72b6\u6001\uff0c\u4e0d\u7528\u6bcf\u4e2arecursion call\u90fdpass\u4e00\u6b21\u3002 \u505a\u5b8c\u8fd9\u9898\u540e\uff0c\u91cd\u65b0\u505acourse...Read more\" \/>\n<meta property=\"og:url\" content=\"https:\/\/feellikelearning.com\/index.php\/2020\/06\/20\/leetcode-269-alien-dictionary-solution\/\" \/>\n<meta property=\"og:site_name\" content=\"Feel Like Learning\" \/>\n<meta property=\"article:published_time\" content=\"2020-06-20T17:20:18+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2020-06-20T22:10:12+00:00\" \/>\n<meta name=\"author\" content=\"feellikelearning\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"feellikelearning\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" 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Alien Dictionary \u89e3\u6cd5 | Feel Like Learning","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/feellikelearning.com\/index.php\/2020\/06\/20\/leetcode-269-alien-dictionary-solution\/","og_locale":"en_US","og_type":"article","og_title":"\u7b97\u6cd5\u7ec3\u4e60 Leetcode \u529b\u6263 269. 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