#1739. [Usaco2005 mar]Space Elevator 太空电梯

题目描述

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.

牛们要到太空去了！他们打算建造一座太空电梯来送他们进入轨道．

有K(1≤K≤400)神方块，第i种有一个特定的高度hi(l≤hi≤100)，一定的存量ci(l≤ci≤10).为防宇宙射线的破坏，第i种方块的任何部分不能超过高度ai(l≤ai≤40000)． 请用这些方块堆出最高的太空电梯．

输入格式

• 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.

  第1行输入一个整数K.

  接下来K行，每行输入三个整数hi，ai，ci．

输出格式

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

  一个整数，表示最大高度．

样例

样例输入

3  

7 40 3  

5 23 8  

2 52 6  

样例输出

48  

从底部开始，先放3个方块2，之后3个方块1，接下来6个方块3．不能把3个方块1堆到4个方  

块2上，因为这样最高的方块1的顶部高度超过了40.  

数据范围与提示