• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>
            隨筆 - 87  文章 - 279  trackbacks - 0
            <2025年6月>
            25262728293031
            1234567
            891011121314
            15161718192021
            22232425262728
            293012345

            潛心看書研究!

            常用鏈接

            留言簿(19)

            隨筆分類(81)

            文章分類(89)

            相冊

            ACM OJ

            My friends

            搜索

            •  

            積分與排名

            • 積分 - 217836
            • 排名 - 117

            最新評論

            閱讀排行榜

            評論排行榜

            1018. A Binary Apple Tree
            Time Limit: 1.0 second
            Memory Limit: 16 MB

            Let's imagine how apple tree looks in binary computer world. You're right, it looks just like a binary tree, i.e. any biparous branch splits up to exactly two new branches. We will enumerate by natural numbers the root of binary apple tree, points of branching and the ends of twigs. This way we may distinguish different branches by their ending points. We will assume that root of tree always is numbered by 1 and all numbers used for enumerating are numbered in range from 1 to N, where N is the total number of all enumerated points. For instance in the picture below N is equal to 5. Here is an example of an enumerated tree with four branches:

               2   5
            \ /
            3   4
            \ /
            1
            
            As you may know it's not convenient to pick an apples from a tree when there are too much of branches. That's why some of them should be removed from a tree. But you are interested in removing branches in the way of minimal loss of apples. So your are given amounts of apples on a branches and amount of branches that should be preserved. Your task is to determine how many apples can remain on a tree after removing of excessive branches.

             

            Input

            First line of input contains two numbers: N and Q (1 ≤ QN, 1 < N ≤ 100). N denotes the number of enumerated points in a tree. Q denotes amount of branches that should be preserved. Next N-1 lines contains descriptions of branches. Each description consists of a three integer numbers divided by spaces. The first two of them define branch by it's ending points. The third number defines the number of apples on this branch. You may assume that no branch contains more than 30000 apples.

            Output

            Output file should contain the only number — amount of apples that can be preserved. And don't forget to preserve tree's root ;-)

            Sample

            input
            output
            5 2
                        1 3 1
                        1 4 10
                        2 3 20
                        3 5 20
                        
            21
                        

            Problem Source: Ural State University Internal Contest '99 #2
            #include <iostream>
            using namespace std;

            const int MAXN = 110;
            const int MAXQ = 110;

            int n, q;
            int d[MAXN][MAXQ];
            int g[MAXN][MAXN], deg[MAXN], nw[MAXN], son[MAXN][2];
            int root;
            int f[MAXN], isleaf[MAXN];

            inline 
            int maxt(int a, int b) {
                
            return a > b ? a : b;
            }


            void DFS(int v) {
                
            int i, t = 0;
                
            for (i=1; i<=n; i++{
                    
            if (g[v][i] != -1 && !f[i]) {
                        son[v][t
            ++= i;
                        f[i] 
            = 1;
                        nw[i] 
            = g[v][i];
                        DFS(i);
                    }

                }

                
            if (!t) isleaf[v] = 1;
            }


            void buildT() {
                
            int i;
                
            for (i=1; i<=n; i++{
                    
            if (deg[i] == 2{
                        root 
            = i;
                        
            break;
                    }

                }

                f[root] 
            = 1; nw[root] = 0;
                DFS(root);
            }


            int DP(int ti, int tl) {
                
            if (tl <= 0return 0;
                
            if (d[ti][tl] != -1return d[ti][tl];
                
            if (isleaf[ti]) return nw[ti];
                
            int k, tmp = 0;
                
            for (k=0; k<tl; k++{
                    tmp 
            = maxt(tmp, DP(son[ti][0], k)+DP(son[ti][1], tl-1-k));
                }

                d[ti][tl] 
            = tmp + nw[ti];
                
            return d[ti][tl];
            }


            int main() {
                
            int i, j, k, x, y, w;
                scanf(
            "%d%d"&n, &q);
                memset(g, 
            -1sizeof(g));
                memset(d, 
            -1sizeof(d));
                
            for (i=0; i<n-1; i++{
                    scanf(
            "%d%d%d"&x, &y, &w); 
                    g[x][y] 
            = g[y][x] = w;
                    deg[x]
            ++, deg[y]++;
                }

                buildT();
                printf(
            "%d\n", DP(root, q+1));

                
            return 0;
            }

            posted on 2007-04-20 20:05 閱讀(1568) 評論(2)  編輯 收藏 引用 所屬分類: ACM題目

            FeedBack:
            # re: ural 1018(簡單的樹狀dp) 2007-09-26 21:49 zYc
            Thank you!  回復  更多評論
              
            # re: ural 1018(簡單的樹狀dp) 2008-02-25 21:24 jkdjfkdjfkdjflasdkjfkjeijfkdsjfkd
            弱弱的膜拜一下  回復  更多評論
              
            老色鬼久久亚洲AV综合| 精品人妻伦一二三区久久| 欧美精品一本久久男人的天堂| 99久久婷婷国产综合亚洲| …久久精品99久久香蕉国产| 久久国产高清字幕中文| 欧美性大战久久久久久| 色妞色综合久久夜夜| 伊人色综合久久天天| 欧美精品乱码99久久蜜桃| 国产精品久久久久久影院| 欧美精品福利视频一区二区三区久久久精品 | 欧美性大战久久久久久| 亚洲国产另类久久久精品黑人| 国产精品久久久久aaaa| 一本色道久久综合狠狠躁| 国内精品久久久久久久coent| 亚洲国产精品无码久久久蜜芽 | 久久免费视频一区| 久久国产精品99精品国产| 亚洲乱码日产精品a级毛片久久| 久久久一本精品99久久精品88| 久久伊人亚洲AV无码网站| 久久国产免费观看精品3| 久久婷婷五月综合97色直播| 久久97久久97精品免视看| 99久久精品国产免看国产一区| 久久久久久精品免费看SSS| 国产精品gz久久久| 久久九九青青国产精品| 无码伊人66久久大杳蕉网站谷歌| 亚洲欧美成人久久综合中文网 | 亚洲中文字幕久久精品无码APP | 久久99国产精一区二区三区| 久久香综合精品久久伊人| 久久精品视频网| 久久影院综合精品| 久久99热只有频精品8| 久久精品毛片免费观看| 国产成人久久AV免费| 91精品国产高清91久久久久久|