Against the Grain→Tools with large market share that Claude Code barely touches, and sharp generational shifts between models.
思路：倒序遍历 2 倍长度 + 取模模拟循环 + 单调栈。用 i % len 映射到真实索引，仅当 i < len 时记录答案。
，详情可参考WPS官方版本下载
US President Donald Trump (R) looks on as US Secretary of Defense Pete Hegseth speaks to the press following US military actions in Venezuela | AFP via Getty Images
12月24日，即将完工的望京西综合交通枢纽。 新京报记者 周怀宗 摄