• <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7月>
            293012345
            6789101112
            13141516171819
            20212223242526
            272829303112
            3456789

            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 - 218110
            • 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(1570) 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
              
            欧美国产精品久久高清| 久久婷婷五月综合色奶水99啪 | 天天综合久久久网| 97精品伊人久久久大香线蕉| 婷婷久久综合九色综合九七| 久久精品亚洲一区二区三区浴池 | 99久久www免费人成精品| 精品无码久久久久久国产| av无码久久久久不卡免费网站 | 久久久黄色大片| 51久久夜色精品国产| 亚洲欧美国产日韩综合久久| 精品午夜久久福利大片| 久久久久久久久无码精品亚洲日韩| 久久夜色精品国产亚洲| 久久久久久久精品成人热色戒| 国产成人久久激情91| 久久亚洲精品国产精品| 久久人人爽人人爽人人片AV不| 免费观看成人久久网免费观看| 欧美日韩精品久久久久| 久久精品国产精品亜洲毛片| 国产999精品久久久久久| 久久电影网2021| 欧美黑人激情性久久| 久久久久国产精品嫩草影院| 97久久国产亚洲精品超碰热| 亚洲乱码中文字幕久久孕妇黑人| 久久亚洲精品成人无码网站| 久久午夜电影网| 亚洲国产精久久久久久久| 国产精品久久久久jk制服| 人妻精品久久久久中文字幕69| 久久人人爽人人爽人人片AV不| 国产精品无码久久久久| 国产精品美女久久久久av爽| 国产精品欧美久久久天天影视| 99精品国产在热久久 | 婷婷久久综合九色综合绿巨人| 亚洲精品综合久久| 国产精品久久新婚兰兰|