A - Space Elevator

Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u

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Description

The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K (1 <= K <= 400) different types of blocks with which to build the tower. Each block of type i has height h_i (1 <= h_i <= 100) and is available in quantity c_i (1 <= c_i <= 10). Due to possible damage caused by cosmic rays, no part of a block of type i can exceed a maximum altitude a_i (1 <= a_i <= 40000). 

Help the cows build the tallest space elevator possible by stacking blocks on top of each other according to the rules.

Input

* Line 1: A single integer, K 

* Lines 2..K+1: Each line contains three space-separated integers: h_i, a_i, and c_i. Line i+1 describes block type i.

Output

* Line 1: A single integer H, the maximum height of a tower that can be built

Sample Input

37 40 35 23 82 52 6

Sample Output

48 题意:有一群牛要上太空,他们计划建一个太空梯(用一些石头垒),他们有k种不同类型的石头,每一种石头的高度为h,数量为c,由于会受到太空辐射,每一种石头不能超过这种石头的最大建造高度a,求解利用这些石头所能修建的太空梯的最高的高度.  多重背包问题,与一般的多重背包问题所不同的知识多了一个限制条件就是某些"物品"叠加起来的"高度"不能超过一个值,于是我们可以对他们的最高可能达到高度进行排序,然后就是一般的多重背包问题了 思路： 首先是录入数据，这一点比较简单，但是最好用scanf，因为它比cin快； 录入之后对各个数据按照最大的使用高度进行排序，就会转化成一个一般的多重背包为题，一开始我是用原始的多重背包做的麻烦并且也没有A了，最后看了一下题解，是因为每种块的使用个数的计算处理不当；

1 #include 
         
           2 #include
          
            3 #include
           
             4 #include
            
              5 #include
             
               6 #include
              
                7 using namespace std; 8 int a[40005]; 9 struct node10 {11 int h;12 int max;13 int shu;14 };15 node num[40005];16 int dp[40005];17 bool cmp(node a,node b)18 {19 return a.max
               
                >k;30 for(i=0;i