http://acm.hdu.edu.cn/showproblem.php?pid=5037 网络赛 北京 比较难的题 Frog Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 99    Accepted Submission(s): 11 Problem Description Once upon a time, there is…

话说这题读起来真费劲啊,估计很多人做不出来就是因为题读不懂...... 从题目中提取的几点关键点: 题目背景就是银河系(Rho Galaxy)中的星球都是绕着他们的质心(center of mass)转的(妈蛋就是这里啊,质心是个什么鬼...,其实就是所有点的值的算术平均值). 现在你可以从一个银河系中的所有星球中转移其中的k个(具体这个转移的意思你可以理解成把他们移到剩下星球的质心上,这样对剩余的整体不会产生影响,当然这也等价于把这k个星球直接删了),然后使剩下的星球让这个The moment…

Frog Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 4467    Accepted Submission(s): 1069 Problem Description Once upon a time, there is a little frog called Matt. One day, he came to a river.…

Once upon a time, there is a little frog called Matt. One day, he came to a river. The river could be considered as an axis.Matt is standing on the left bank now (at position 0). He wants to cross the river, reach the right bank (at position M). But…