Rethinking the Generation of High-Quality CoT Data from the Perspective of LLM-Adaptive Question Difficulty Grading. - Qianjin Yu; Keyu Wu; Zihan Chen; Chushu Zhang; Manlin Mei; Lingjun Huang; Fang Tan; Yongsheng Du; Kunlin Liu; Yurui Zhu (CoRR, 2025)