这里面包含算法分析的一个术语，不能简单直译。
k-competitive 通常用于描述实时算法的时间性能。若一个问题的在线算法的（时间）性能为Pn、其最优的离线算法性能为Pf，则当 Pn / Pf <= k对于任何输入序列都满足的话，则称该在线算法是k-competitive。
在线和离线的区别在于：在线算法的输入序列是在处理的同时依次输入的，处理当前部分序列时对后续序列毫无所知。而离线算法是在已知整个序列之后，对该序列采取最优的处理方式。好比玩一个实时游戏，前者相当于正常玩法，后者类似开挂玩家。
参考：
“An algorithm is said to be on-line if it receives its input in a sequence of requests, and must service each request as it arrives, without any knowledge of the future. (Many fundamental problems in computer science are inherently online, including memory management, processor scheduling, load balancing and routing. )
An on-line algorithm is said to be c-competitive if on each input its performanceis within a factor of c of the performance of the optimal off-line algorithm on that input. ”
