思路 前缀和,二分起点或中点 wa的原因: 解不存在输出0 讲的很好:https://blog.youkuaiyun.com/sunnyyoona/article/details/25840365 https://blog.youkuaiyun.com/zy691357966/article/details/40212215 尺取法讲解: https://blog.youkuaiyun.com/qq_36553623/article/details/69055007 https://blog.youkuaiyun.com/zw1996/article/details/52089894