{"id":3014,"date":"2020-02-22T16:06:04","date_gmt":"2020-02-22T08:06:04","guid":{"rendered":"http:\/\/www.sniper97.cn\/?p=3014"},"modified":"2020-02-22T16:06:04","modified_gmt":"2020-02-22T08:06:04","slug":"%e3%80%90leetcode%e3%80%910063-%e4%b8%8d%e5%90%8c%e8%b7%af%e5%be%84ii","status":"publish","type":"post","link":"http:\/\/www.sniper97.cn\/index.php\/note\/algorithm\/3014\/","title":{"rendered":"\u3010LeetCode\u30110063 \u4e0d\u540c\u8def\u5f84II"},"content":{"rendered":"\n<p><a href=\"https:\/\/leetcode-cn.com\/problems\/unique-paths-ii\/\">https:\/\/leetcode-cn.com\/problems\/unique-paths-ii\/<\/a><\/p>\n\n\n<pre class=\"wp-block-preformatted\"># -*- coding:utf-8 -*-\n<em>\n<\/em>class Solution(object):\n    def uniquePathsWithObstacles(self, obstacleGrid):\n        <em>\"\"\"\n        <\/em><strong><em>:type<\/em><\/strong><em> obstacleGrid: List[List[int]]\n        <\/em><strong><em>:rtype<\/em><\/strong><em>: int\n        \"\"\"\n        <\/em>def is_available(x, y):\n            <em>\"\"\"\n            \u9a8c\u8bc1\u5f53\u524d\u4f4d\u7f6e\u662f\u5426\u53ef\u8fbe\n            <\/em><strong><em>:param<\/em><\/strong><em> x:\n            <\/em><strong><em>:param<\/em><\/strong><em> y:\n            <\/em><strong><em>:return<\/em><\/strong><em>:\n            \"\"\"\n            <\/em>if x &lt; len(obstacleGrid) and y &lt; len(obstacleGrid[0]) and obstacleGrid[x][y] == 0:\n                return True\n            else:\n                return False\n        def dfs(x, y):\n            <em>\"\"\"\n            \u6df1\u5ea6\u4f18\u5148\u904d\u5386\n            <\/em><strong><em>:param<\/em><\/strong><em> x:\n            <\/em><strong><em>:param<\/em><\/strong><em> y:\n            <\/em><strong><em>:return<\/em><\/strong><em>:\n            \"\"\"\n            <\/em>if x == len(obstacleGrid) - 1 and y == len(obstacleGrid[0]) - 1:\n                return 1\n            res = 0\n            for ii, jj in [(0, 1), (1, 0)]:\n                if is_available(x + ii, y + jj):\n                    res += dfs(x + ii, y + jj)\n            return res\n        # if len(obstacleGrid) == 1:\n        #     if sum(obstacleGrid[0]) >= 1:\n        #         return 0\n        #     return 1\n        if obstacleGrid[0][0] == 1:\n            return 0\n        res = dfs(0, 0)\n        return res\nif __name__ == '__main__':\n    obta = [\n        [0, 0, 0],\n        [0, 1, 0],\n        [0, 0, 0]\n    ]\n    print(Solution().uniquePathsWithObstacles(obta))\n<\/pre>\n\n\n<p><strong>\u601d\u8def<\/strong>\uff1a\u521a\u5f00\u59cb\u6211\u60f3\u7684\u662f\u6df1\u641c\uff0c\u867d\u7136\u80fd\u5b8c\u6210\uff0c\u4f46\u662f\u8d85\u65f6\u4e86\uff0c\u90a3\u5c31dp\u5457\u3002<\/p>\n\n\n<p>dp\u7684\u601d\u8def\u662f\u5148\u5904\u7406\u4e00\u884c\uff0c\u5982\u679c\u5f53\u524d\u4f4d\u7f6e\u662f\u8def\u969c\uff0c\u5219\u4e3a0\uff0c\u5426\u5219\u4e3a\u5de6\u548c\u4e0a\u7684\u548c\u3002<\/p>\n\n\n<p>\u5efa\u8bae\u91c7\u7528\u591a\u4e00\u884c\u5217\u7684dp\u6570\u7ec4\u6765\u7edf\u4e00\u5316\u64cd\u4f5c\u3002<\/p>\n\n\n<p>\u4e5f\u53ef\u4ee5\u4f7f\u7528\u4f18\u5316\u5185\u5b58\u7684dp\u6570\u7ec4\u3002dp\u4ee3\u8868\u5f53\u524d\u884c\u7684\u76f8\u5173\u4fe1\u606f\uff0c\u56e0\u4e3a\u7b2c\u4e00\u5217\u603b\u8981\u548c\u5f53\u524d\u884c\u7684\u4e0a\u4e00\u884c\u4e00\u81f4\uff08\u56e0\u4e3a\u53ea\u80fd\u5411\u4e0b\u5230\u8fd9\u91cc\uff09\uff0c\u6240\u4ee5\u5b8c\u5168\u53ef\u4ee5\u76f4\u63a5\u7ee7\u7eed\u4f7f\u7528\u4e0a\u4e00\u884c\u7684dp\u72b6\u6001\u6765\u8ba1\u7b97\u4e0b\u4e00\u884c\u3002<\/p>\n\n\n<p>\u8fd9\u91cc\u4e4b\u6240\u4ee5dp\u521d\u59cb\u5316\u4e3am+1\u4e2a\u5c31\u662f\u8981\u5f53j==0\u65f6j-1\u80fd\u591f\u7edf\u4e00\u64cd\u4f5c\uff0c\u653e\u5230[1]\u524d\u9762\u4e5f\u4e00\u6837<\/p>\n\n\n<pre class=\"wp-block-preformatted\">def uni(self, obstacleGrid):<br \/>    m, n = len(obstacleGrid[0]), len(obstacleGrid)<br \/>    dp = [1] + [0] * m<br \/>    for i in range(0, n):<br \/>        for j in range(0, m):<br \/>            dp[j] = 0 if obstacleGrid[i][j] else dp[j] + dp[j - 1]<br \/>    return dp[-2]<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>https:\/\/leetcode-cn.com\/problems\/unique-paths-ii\/  [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[10],"tags":[],"views":1558,"_links":{"self":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/posts\/3014"}],"collection":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/comments?post=3014"}],"version-history":[{"count":0,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/posts\/3014\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/media?parent=3014"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/categories?post=3014"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.sniper97.cn\/index.php\/wp-json\/wp\/v2\/tags?post=3014"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}