{"id":613,"date":"2020-09-26T11:03:26","date_gmt":"2020-09-26T03:03:26","guid":{"rendered":"http:\/\/39.96.58.60\/?p=613"},"modified":"2022-10-18T16:45:04","modified_gmt":"2022-10-18T08:45:04","slug":"leetcode-303-%e5%8c%ba%e5%9f%9f%e5%92%8c%e6%a3%80%e7%b4%a2-%e6%95%b0%e7%bb%84%e4%b8%8d%e5%8f%af%e5%8f%98","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=613","title":{"rendered":"Leetcode 303. \u533a\u57df\u548c\u68c0\u7d22 &#8211; \u6570\u7ec4\u4e0d\u53ef\u53d8"},"content":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u6574\u6570\u6570\u7ec4 &nbsp;<em>nums<\/em>\uff0c\u6c42\u51fa\u6570\u7ec4\u4ece\u7d22\u5f15&nbsp;<em>i&nbsp;<\/em>\u5230&nbsp;<em>j&nbsp;&nbsp;<\/em>(<em>i<\/em>&nbsp;\u2264&nbsp;<em>j<\/em>) \u8303\u56f4\u5185\u5143\u7d20\u7684\u603b\u548c\uff0c\u5305\u542b&nbsp;<em>i,&nbsp; j&nbsp;<\/em>\u4e24\u70b9\u3002<\/p>\n<p><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n<pre>\u7ed9\u5b9a nums = [-2, 0, 3, -5, 2, -1]\uff0c\u6c42\u548c\u51fd\u6570\u4e3a sumRange()\n\n\n\nsumRange(0, 2) -&gt; 1\n\nsumRange(2, 5) -&gt; -1\n\nsumRange(0, 5) -&gt; -3<\/pre>\n<p><strong>\u8bf4\u660e:<\/strong><\/p>\n<ol>\n<li>\u4f60\u53ef\u4ee5\u5047\u8bbe\u6570\u7ec4\u4e0d\u53ef\u53d8\u3002<\/li>\n<li>\u4f1a\u591a\u6b21\u8c03\u7528&nbsp;<em>sumRange<\/em>&nbsp;\u65b9\u6cd5\u3002<\/li>\n<\/ol>\n<p>**\u96be\u5ea6**: Easy<\/p>\n<p>**\u6807\u7b7e**: \u52a8\u6001\u89c4\u5212\u3001<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism undefined-numbers lang-python\" data-lang=\"Python\"><code>\n# -*- coding: utf-8 -*-\n# @Author  : LG\n\n\"\"\"\n\u6267\u884c\u7528\u65f6\uff1a88 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8695.50% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a17.3 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8617.70% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u52a8\u6001\u89c4\u5212\n    [\"NumArray\",\"sumRange\",\"sumRange\",\"sumRange\"]\n    [[[-2,0,3,-5,2,-1]],[0,2],[2,5],[0,5]]\n\n    \u8981\u6c42 (i, j)\u7684\u548c\uff0c\u53ef\u4ee5\u770b\u505a\u6c42(0, j)-(0, i)\uff0c\u524dj\u4e2a\u7684\u548c-\u524di\u4e2a\u7684\u548c\u3002\n    [-2, 0, 3, -5, 2, -1]\n         i\n\n    \u4f7f\u7528\u52a8\u6001\u89c4\u5212\u8ba1\u7b97\u524di\u4e2a\u7684\u548c\n    dp[i] = dp[i-1] + nums[i]\n\n\"\"\"\nclass NumArray:\n\n    def __init__(self, nums: List[int]):\n        self.n = len(nums)\n        if self.n &gt;= 1:\n            self.dp = [[] for _ in range(self.n)]\n            self.dp[0] = nums[0]\n            for i in range(1, self.n):\n                self.dp[i] = self.dp[i - 1] + nums[i]\n\n    def sumRange(self, i: int, j: int) -&gt; int:\n        if self.n &lt; 1:\n            return None\n        if i == 0:\n            return self.dp[j]\n        else:\n            return self.dp[j] - self.dp[i - 1]\n\n# Your NumArray object will be instantiated and called as such:\n# obj = NumArray(nums)\n# param_1 = obj.sumRange(i,j)<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u6574\u6570\u6570\u7ec4 &nbsp;nums\uff0c\u6c42\u51fa\u6570\u7ec4\u4ece\u7d22\u5f15&nbsp;i&nbsp;\u5230&nbsp;j&nbsp;&#038;&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":[],"categories":[11,1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/613"}],"collection":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=613"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/613\/revisions"}],"predecessor-version":[{"id":614,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/613\/revisions\/614"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=613"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}