{"id":2676,"date":"2022-04-09T16:37:26","date_gmt":"2022-04-09T08:37:26","guid":{"rendered":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2676"},"modified":"2022-04-09T16:37:26","modified_gmt":"2022-04-09T08:37:26","slug":"dp%e7%ac%ac12%e5%a4%a9","status":"publish","type":"post","link":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2676","title":{"rendered":"dp\u7b2c12\u5929"},"content":{"rendered":"\n

\u641e\u4e24\u9053\u7b80\u5355\u9898<\/p>\n\n\n\n

118. \u6768\u8f89\u4e09\u89d2<\/a><\/p>\n\n\n\n

\n\/**\n<\/em> 118. \u6768\u8f89\u4e09\u89d2\n<\/em> \u7ed9\u5b9a\u4e00\u4e2a\u975e\u8d1f\u6574\u6570 numRows\uff0c\u751f\u6210\u300c\u6768\u8f89\u4e09\u89d2\u300d\u7684\u524d numRows \u884c\u3002\n<\/em>\n<\/em> \u5728\u300c\u6768\u8f89\u4e09\u89d2\u300d\u4e2d\uff0c\u6bcf\u4e2a\u6570\u662f\u5b83\u5de6\u4e0a\u65b9\u548c\u53f3\u4e0a\u65b9\u7684\u6570\u7684\u548c\u3002\n<\/em>\n<\/em>\n<\/em> \u793a\u4f8b 1:\n<\/em>\n<\/em> \u8f93\u5165: numRows = 5\n<\/em> \u8f93\u51fa: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]\n<\/em> \u793a\u4f8b 2:\n<\/em>\n<\/em> \u8f93\u5165: numRows = 1\n<\/em> \u8f93\u51fa: [[1]]\n<\/em>\n<\/em>\n<\/em> \u63d0\u793a:\n<\/em>\n<\/em> 1 <= numRows <= 30\n<\/em>\n<\/em> * <\/em>@author <\/em><\/strong>zeroheart\n<\/em> *\n<\/em> *\/\n<\/em>public class Question118 {\n    public List<List<Integer>> generate(int numRows) {\n        List<List<Integer>> res = new ArrayList<>();\n        int[][] dp = new int[numRows][numRows];\n        for(int i = 0; i<numRows; i++){\n            dp[i][0] = 1;\n            dp[i][i] = 1;\n        }\n        List l0 = new ArrayList();\n        l0.add(1);\n        res.add(l0);\n        for(int i=1; i<numRows; i++){\n            List list = new ArrayList();\n            list.add(1);\n            for(int j=1; j<=i; j++){\n                dp[i][j] = dp[i-1][j-1]+dp[i-1][j];\n                list.add(dp[i][j]);\n            }\n            res.add(list);\n        }\n        return res;\n    }\n\n    public static void main(String[] args) {\n    }\n}<\/pre>\n\n\n\n
119. \u6768\u8f89\u4e09\u89d2 II<\/a><\/p>\n\n\n\n
\u8fd9\u9898\u662f\u8f93\u51fa\u67d0\u4e00\u884c\u7684\u503c\u3002\u3002\u3002\u4e0a\u9762\u7684\u6539\u4e00\u4e0b\u5c31\u884c\u3002\u3002\u3002<\/p>\n\n\n\n

\/**
<\/em> 119. \u6768\u8f89\u4e09\u89d2 II
<\/em> \u7ed9\u5b9a\u4e00\u4e2a\u975e\u8d1f\u7d22\u5f15 rowIndex\uff0c\u8fd4\u56de\u300c\u6768\u8f89\u4e09\u89d2\u300d\u7684\u7b2c rowIndex \u884c\u3002
<\/em>
<\/em> \u5728\u300c\u6768\u8f89\u4e09\u89d2\u300d\u4e2d\uff0c\u6bcf\u4e2a\u6570\u662f\u5b83\u5de6\u4e0a\u65b9\u548c\u53f3\u4e0a\u65b9\u7684\u6570\u7684\u548c\u3002
<\/em>
<\/em>
<\/em> \u793a\u4f8b 1:
<\/em>
<\/em> \u8f93\u5165: rowIndex = 3
<\/em> \u8f93\u51fa: [1,3,3,1]
<\/em> \u793a\u4f8b 2:
<\/em>
<\/em> \u8f93\u5165: rowIndex = 0
<\/em> \u8f93\u51fa: [1]
<\/em> \u793a\u4f8b 3:
<\/em>
<\/em> \u8f93\u5165: rowIndex = 1
<\/em> \u8f93\u51fa: [1,1]
<\/em>
<\/em>
<\/em> \u63d0\u793a:
<\/em>
<\/em> 0 <= rowIndex <= 33
<\/em>
<\/em>
<\/em> \u8fdb\u9636\uff1a
<\/em>
<\/em> \u4f60\u53ef\u4ee5\u4f18\u5316\u4f60\u7684\u7b97\u6cd5\u5230 O(rowIndex) \u7a7a\u95f4\u590d\u6742\u5ea6\u5417\uff1f
<\/em>
<\/em> * <\/em>@author <\/em><\/strong>zeroheart
<\/em> *
<\/em> *\/
<\/em>public class Question119 {
    public List<Integer> getRow(int rowIndex) {
        int numRows = rowIndex + 1;
        List<List<Integer>> res = new ArrayList<>();
        int[][] dp = new int[numRows][numRows];
        for(int i = 0; i<numRows; i++){
            dp[i][0] = 1;
            dp[i][i] = 1;
        }
        List l0 = new ArrayList();
        l0.add(1);
        res.add(l0);
        for(int i=1; i<numRows; i++){
            List list = new ArrayList();
            list.add(1);
            for(int j=1; j<=i; j++){
                dp[i][j] = dp[i-1][j-1]+dp[i-1][j];
                list.add(dp[i][j]);
            }
            res.add(list);
        }

        return res.get(rowIndex);
    }

    public static void main(String[] args) {
    }
}<\/pre>\n","protected":false},"excerpt":{"rendered":"
\u641e\u4e24\u9053\u7b80\u5355\u9898 118. \u6768\u8f89\u4e09\u89d2 \/** 118. \u6768\u8f89\u4e09\u89d2 \u7ed9\u5b9a\u4e00\u4e2a\u975e\u8d1f\u6574\u6570 numRows\uff0c\u751f\u6210\u300c\u6768\u8f89\u4e09\u89d2 […]<\/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":[158],"_links":{"self":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2676"}],"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=2676"}],"version-history":[{"count":4,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2676\/revisions"}],"predecessor-version":[{"id":2680,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2676\/revisions\/2680"}],"wp:attachment":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2676"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2676"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2676"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}