RT.这题翻译是我写的，结果锅了，我谢罪/kk
原题中的 (∑i=1x−1min(b,ti))+(∑i=x+k+1nmin(a,ti))(\sum\limits_{i=1}^{x-1} \min(b,t_i)) + (\sum\limits_{i=x+k+1}^{n} \min(a,t_i))(i=1∑x−1min(b,ti))+(i=x+k+1∑nmin(a,ti)) 应改成 (∑i=1x−1min(b,ti))+(∑i=x+knmin(a,ti))(\sum\limits_{i=1}^{x-1} \min(b,t_i)) + (\sum\limits_{i=x+k}^{n} \min(a,t_i))(i=1∑x−1min(b,ti))+(i=x+k∑nmin(a,ti))
上面那串柿子即 $(\sum\limits_{i=1}^{x-1} \min(b,t_i)) + (\sum\limits_{i=x+k}^{n} \min(a,t_i))$，求修正
$(\sum\limits_{i=1}^{x-1} \min(b,t_i)) + (\sum\limits_{i=x+k}^{n} \min(a,t_i))$
@bzy_
