#P4766. [CERC2014] Outer space invaders
[CERC2014] Outer space invaders
题目描述
The aliens from outer space have (finally!) invaded Earth. Defend yourself, or be disintegrated!
Or assimilated. Or eaten. We are not yet sure.
The aliens follow a known attack pattern. There are attackers, the one appears at time , at distance from you. He must be destroyed no later than at time , or else he will fire his weapon, which will definitely end the fight.
Your weapon is an area-blaster, which can be set to any given power. If fired with power ,it momentarily destroys all aliens at distance or smaller. It also consumes fuel cells.
Determine the minimal cost (measured in fuel cells) of destroying all the aliens, without being killed.
输入格式
The first line of input contains the number of test cases . The descriptions of the test cases follow:
Each test case starts with a line containing the number of aliens . Of the next lines, the one contains three integers $a_i, b_i, d_i, (1 \le a_i < b_i \le 10 000, 1 \le d_i \le 10 000)$.
The alien appears at time , is idle until , and his distance from you is .
输出格式
For each test case, output one line containing the minimum number of cells needed to destroy all the aliens.
题目大意
题目描述
来自外太空的外星人(最终)入侵了地球。保卫自己,或者解体,被他们同化,或者成为食物。迄今为止,我们无法确定。
外星人遵循已知的攻击模式。有 个外星人进攻,第 个进攻的外星人会在时间 出现,距离你的距离为 ,它必须在时间 前被消灭,否则被消灭的会是你。
你的武器是一个区域冲击波器,可以设置任何给定的功率。如果被设置了功率 ,它会瞬间摧毁与你的距离在 以内的所有外星人(可以等于),同时它也会消耗 单位的燃料电池。
求摧毁所有外星人的最低成本(消耗多少燃料电池),同时保证自己的生命安全。
输入格式
第一行输入一个数 ,表示有 组数据。
每组数据的第一行为外星人的数量 ()。
接下来 行,每行有三个数 ,表示这个外星人在时间 出现,距离你 ,在 前时刻死亡。
输出格式
共 行,每行输出摧毁所有外星人的最低成本。
1
3
1 4 4
4 7 5
3 4 7
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