2023-01-06:给定一个只由小写字母组成的字符串str,长度为N,给定一个只由0、1组成的数组arr,长度为N,arri等于 0 表示str中i位置的字符不许修改,arri 等于 1表示str中i位置的字符允许修改,给定一个正数m,表示在任意允许修改的...
Rust doesn’t allow us to mark only certain fields as mutable. You can only mark whole struct as mutable or immutable.
For same variable name, the former is shadowed by the latter