{"id":2708,"date":"2022-04-11T23:51:51","date_gmt":"2022-04-11T15:51:51","guid":{"rendered":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2708"},"modified":"2022-04-12T23:24:11","modified_gmt":"2022-04-12T15:24:11","slug":"%e7%ae%97%e6%b3%95%e5%9f%ba%e7%a1%80%e7%ac%ac%e4%ba%8c%e5%a4%a9","status":"publish","type":"post","link":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2708","title":{"rendered":"\u7b97\u6cd5\u57fa\u7840\u7b2c\u4e8c\u5929"},"content":{"rendered":"\n

153. \u5bfb\u627e\u65cb\u8f6c\u6392\u5e8f\u6570\u7ec4\u4e2d\u7684\u6700\u5c0f\u503c<\/a><\/p>\n\n\n\n

\/**\n 153. \u5bfb\u627e\u65cb\u8f6c\u6392\u5e8f\u6570\u7ec4\u4e2d\u7684\u6700\u5c0f\u503c\n \u5df2\u77e5\u4e00\u4e2a\u957f\u5ea6\u4e3a n \u7684\u6570\u7ec4\uff0c\u9884\u5148\u6309\u7167\u5347\u5e8f\u6392\u5217\uff0c\u7ecf\u7531 1 \u5230 n \u6b21 \u65cb\u8f6c \u540e\uff0c\u5f97\u5230\u8f93\u5165\u6570\u7ec4\u3002\u4f8b\u5982\uff0c\u539f\u6570\u7ec4 nums = [0,1,2,4,5,6,7] \u5728\u53d8\u5316\u540e\u53ef\u80fd\u5f97\u5230\uff1a\n \u82e5\u65cb\u8f6c 4 \u6b21\uff0c\u5219\u53ef\u4ee5\u5f97\u5230 [4,5,6,7,0,1,2]\n \u82e5\u65cb\u8f6c 7 \u6b21\uff0c\u5219\u53ef\u4ee5\u5f97\u5230 [0,1,2,4,5,6,7]\n \u6ce8\u610f\uff0c\u6570\u7ec4 [a[0], a[1], a[2], ..., a[n-1]] \u65cb\u8f6c\u4e00\u6b21 \u7684\u7ed3\u679c\u4e3a\u6570\u7ec4 [a[n-1], a[0], a[1], a[2], ..., a[n-2]] \u3002\n\n \u7ed9\u4f60\u4e00\u4e2a\u5143\u7d20\u503c \u4e92\u4e0d\u76f8\u540c \u7684\u6570\u7ec4 nums \uff0c\u5b83\u539f\u6765\u662f\u4e00\u4e2a\u5347\u5e8f\u6392\u5217\u7684\u6570\u7ec4\uff0c\u5e76\u6309\u4e0a\u8ff0\u60c5\u5f62\u8fdb\u884c\u4e86\u591a\u6b21\u65cb\u8f6c\u3002\u8bf7\u4f60\u627e\u51fa\u5e76\u8fd4\u56de\u6570\u7ec4\u4e2d\u7684 \u6700\u5c0f\u5143\u7d20 \u3002\n\n \u4f60\u5fc5\u987b\u8bbe\u8ba1\u4e00\u4e2a\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(log n) \u7684\u7b97\u6cd5\u89e3\u51b3\u6b64\u95ee\u9898\u3002\n\n\n\n \u793a\u4f8b 1\uff1a\n\n \u8f93\u5165\uff1anums = [3,4,5,1,2]\n \u8f93\u51fa\uff1a1\n \u89e3\u91ca\uff1a\u539f\u6570\u7ec4\u4e3a [1,2,3,4,5] \uff0c\u65cb\u8f6c 3 \u6b21\u5f97\u5230\u8f93\u5165\u6570\u7ec4\u3002\n \u793a\u4f8b 2\uff1a\n\n \u8f93\u5165\uff1anums = [4,5,6,7,0,1,2]\n \u8f93\u51fa\uff1a0\n \u89e3\u91ca\uff1a\u539f\u6570\u7ec4\u4e3a [0,1,2,4,5,6,7] \uff0c\u65cb\u8f6c 4 \u6b21\u5f97\u5230\u8f93\u5165\u6570\u7ec4\u3002\n \u793a\u4f8b 3\uff1a\n\n \u8f93\u5165\uff1anums = [11,13,15,17]\n \u8f93\u51fa\uff1a11\n \u89e3\u91ca\uff1a\u539f\u6570\u7ec4\u4e3a [11,13,15,17] \uff0c\u65cb\u8f6c 4 \u6b21\u5f97\u5230\u8f93\u5165\u6570\u7ec4\u3002\n\n\n \u63d0\u793a\uff1a\n\n n == nums.length\n 1 <= n <= 5000\n -5000 <= nums[i] <= 5000\n nums \u4e2d\u7684\u6240\u6709\u6574\u6570 \u4e92\u4e0d\u76f8\u540c\n nums \u539f\u6765\u662f\u4e00\u4e2a\u5347\u5e8f\u6392\u5e8f\u7684\u6570\u7ec4\uff0c\u5e76\u8fdb\u884c\u4e86 1 \u81f3 n \u6b21\u65cb\u8f6c\n\n * @author zeroheart\n *\n *\/\npublic class Question153 {\n\n    public int findMin(int[] nums) {\n        int m = nums.length;\n        int low = 0; int high = m - 1;\n        while (low <= high){\n            int mid = low + (high - low) \/ 2;\n            if(nums[mid] < nums[high]) {\n                high = mid; \/\/ \u6b63\u5e382\u5206\u8fd9\u91cc\u8981-1\u7684\n            }else {\n                low = mid + 1;\n            }\n        }\n        return nums[high];\n    }\n\n}\n<\/pre>\n\n\n\n
162. \u5bfb\u627e\u5cf0\u503c<\/a><\/p>\n\n\n\n
\u722c\u5761\u6cd5\u3002\u3002<\/p>\n\n\n\n
\u770b\u5230log(n)\uff0c\u5f88\u6709\u53ef\u80fd\u662f\u4e8c\u5206\uff0c\u54c8\u54c8<\/p>\n\n\n\n

\/**
<\/em> 162. \u5bfb\u627e\u5cf0\u503c
<\/em> \u5cf0\u503c\u5143\u7d20\u662f\u6307\u5176\u503c\u4e25\u683c\u5927\u4e8e\u5de6\u53f3\u76f8\u90bb\u503c\u7684\u5143\u7d20\u3002
<\/em>
<\/em> \u7ed9\u4f60\u4e00\u4e2a\u6574\u6570\u6570\u7ec4 nums\uff0c\u627e\u5230\u5cf0\u503c\u5143\u7d20\u5e76\u8fd4\u56de\u5176\u7d22\u5f15\u3002\u6570\u7ec4\u53ef\u80fd\u5305\u542b\u591a\u4e2a\u5cf0\u503c\uff0c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u8fd4\u56de \u4efb\u4f55\u4e00\u4e2a\u5cf0\u503c \u6240\u5728\u4f4d\u7f6e\u5373\u53ef\u3002
<\/em>
<\/em> \u4f60\u53ef\u4ee5\u5047\u8bbe nums[-1] = nums[n] = -\u221e \u3002
<\/em>
<\/em> \u4f60\u5fc5\u987b\u5b9e\u73b0\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(log n) \u7684\u7b97\u6cd5\u6765\u89e3\u51b3\u6b64\u95ee\u9898\u3002
<\/em>
<\/em>
<\/em>
<\/em> \u793a\u4f8b 1\uff1a
<\/em>
<\/em> \u8f93\u5165\uff1anums = [1,2,3,1]
<\/em> \u8f93\u51fa\uff1a2
<\/em> \u89e3\u91ca\uff1a3 \u662f\u5cf0\u503c\u5143\u7d20\uff0c\u4f60\u7684\u51fd\u6570\u5e94\u8be5\u8fd4\u56de\u5176\u7d22\u5f15 2\u3002
<\/em> \u793a\u4f8b 2\uff1a
<\/em>
<\/em> \u8f93\u5165\uff1anums = [1,2,1,3,5,6,4]
<\/em> \u8f93\u51fa\uff1a1 \u6216 5
<\/em> \u89e3\u91ca\uff1a\u4f60\u7684\u51fd\u6570\u53ef\u4ee5\u8fd4\u56de\u7d22\u5f15 1\uff0c\u5176\u5cf0\u503c\u5143\u7d20\u4e3a 2\uff1b
<\/em> \u6216\u8005\u8fd4\u56de\u7d22\u5f15 5\uff0c \u5176\u5cf0\u503c\u5143\u7d20\u4e3a 6\u3002
<\/em>
<\/em>
<\/em> \u63d0\u793a\uff1a
<\/em>
<\/em> 1 <= nums.length <= 1000
<\/em> -231 <= nums[i] <= 231 - 1
<\/em> \u5bf9\u4e8e\u6240\u6709\u6709\u6548\u7684 i \u90fd\u6709 nums[i] != nums[i + 1]
<\/em>
<\/em> * <\/em>@author <\/em><\/strong>zeroheart
<\/em> *
<\/em> *\/
<\/em>public class Question162 {

    public int findPeakElement(int[] nums) {

        \/**
<\/em>         * https:\/\/leetcode-cn.com\/problems\/find-peak-element\/solution\/hua-jie-suan-fa-162-xun-zhao-feng-zhi-by-guanpengc\/
<\/em>         * \u603b\u7684\u4e00\u53e5\u8bdd\uff0c\u5f80\u9012\u589e\u7684\u65b9\u5411\u4e0a\uff0c\u4e8c\u5206\uff0c\u4e00\u5b9a\u80fd\u627e\u5230\uff0c\u5f80\u9012\u51cf\u7684\u65b9\u5411\u53ea\u662f\u53ef\u80fd\u627e\u5230\uff0c\u4e5f\u8bb8\u6ca1\u6709\u3002
<\/em>         * \u53c8\u53ef\u4ee5\u79f0\u4e3a\u722c\u5761\u6cd5\uff0c\u8fd4\u56de\u7684\u662flow
<\/em>         *\/
<\/em>
<\/em>        <\/em>int len = nums.length;
        int low = 0; int high = len -1;
        int res = -1;
        while (low < high){ \/\/ \u6ce8\u610f\u533a\u522b
            int mid = low + (high - low) \/ 2;
            if(nums[mid] < nums[mid+1]){
                low = mid + 1; \/\/ \u6bd4\u5927\u5c0f\uff0c\u5411\u4e0a\u722c
            }else {
                high = mid;
            }
        }

        return low;
    }

}<\/pre>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
153. \u5bfb\u627e\u65cb\u8f6c\u6392\u5e8f\u6570\u7ec4\u4e2d\u7684\u6700\u5c0f\u503c \/** 153. \u5bfb\u627e\u65cb\u8f6c\u6392\u5e8f\u6570\u7ec4\u4e2d\u7684\u6700\u5c0f\u503c \u5df2\u77e5\u4e00\u4e2a\u957f\u5ea6\u4e3a n \u7684\u6570\u7ec4 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[155],"tags":[156],"_links":{"self":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2708"}],"collection":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2708"}],"version-history":[{"count":8,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2708\/revisions"}],"predecessor-version":[{"id":2716,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2708\/revisions\/2716"}],"wp:attachment":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2708"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2708"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2708"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}