Working out the train formation plans for technical service stations is an exceptionally large-scale combinatorial optimizing problem, and it is hard to solve with the mathematical method.

技术站列车编组计划编制问题属于超大规模的组合优化问题，求解难度较大。

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Fifty bitcoins are released when that block is done and the work, which involves solving a hard mathematical problem, is completed.

BBC: Rewards set to halve for digital money miners

Mining involves solving a hard mathematical problem and miners typically use large numbers of computers to speed up the number-crunching involved.

BBC: Bitcoin miners generating high energy bills

Mining involves solving a hard mathematical problem and miners typically use large numbers of computers to speed up the number crunching involved.

BBC: Bitcoin miners hit back at cyber-thieves